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David T O'Sullivan

Divorce and separation Attorney at Morristown, NJ

4.6   17 reviews
  • Licensed for 17 years
    State NJ
    Acquired 2006
    Active No misconduct found

We have not found any instances of professional misconduct for this lawyer.

About David

Learn David’s areas of practice.

Practice areas
  1. Divorce and separation
    We handle all aspects of family law including divorce, alimony, child support, domestic violence, adoptions, modifications of orders, DCP&P cases and relocations out of state.

    18 years

  2. Mediation

    18 years

  3. Real estate
    Commercial real estate transactions and litigations. Provider of corporate and commercial real estate services for major corporate users, owners, and investors.

At McElroy, Deutsch, Mulvaney & Carpenter, LLP, we provide comprehensive family law legal services to our clients.  While most "family" law firms focus primarily on divorce and matrimonial related matters, we provide services that extend well beyond the traditional "divorce & matrimonial" law firm.

While we provide professional legal services in the areas of divorce and related matters, we also provide legal services in the areas of:

Estate Planning

Estate Administration

Real Estate -- Commercial and Residential


Personal injury


And many other areas.

If it touches you or your family, we stand ready to assist you with your legal needs.


Graham Curtin, P.A.
4 Headquarters Plaza
P.O. Box 1991
Morristown, NJ, 07960-3756

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4.6 / 5.0
  17 customer reviews
Posted by anonymous | November 11, 2016
This review is from a person who hired this attorney.
| Hired Attorney
Protects your rights
Dave and his team are a caring, compassionate, and knowledgeable group that helped us get through a difficult family case. He cares as deeply about your case as he does about you and all others involved. He is a powerful strategist and zealously protects your right in court. I highly recommend Dave O'Sullivan!!
Posted by Nick | February 4, 2016
This review is from a person who hired this attorney.
| Hired Attorney
The Real Deal!
I really don't know where to start...I have been working with Dave for about a year regarding my case. From day one, he has been open and honest. He gave me great advice and always tried to save any expenses. For Dave, it's not about the money, it's about doing what is right and I truly cannot thank him enough!
Posted by Jayna | June 11, 2014
The BEST Divorce Attorney in NJ!
I met with a number of attorney's regarding my divorce. As soon as I met with Mr. O'Sullivan I immedately felt a level of comfort that I hadn't experienced at any other consultations I previously had. Mr. O'Sullivan was extremely attentive as I spoke about my situation and had a number of great suggestions and offered concrete advice as to how he would handle my highly complex case. Mr. O'Sullivan's knowledge of the laws amazes me . His level of integrity, honesty and professionalism are second to none. When he needs to fight, Mr. O'Sullivan fights hard and aggressively -- he always gives 110% in all that he does and gets RESULTS! No matter what time I reach out to him, Mr. O'Sullivan responds immediately -- he makes himself available to discuss any issues (major or minor) I may have. He always makes me feel as though I am his only priority (even though I know how busy he really is). Mr. O'Sullivan has an outstanding reputation amongst other attorneys and is extremely well respected and highly regarded whenever I mention his name and see him interact with his peers.. Thus far, I have been extremely pleased with the level of service and the results that Dave has achieved with regards to my ongoing, and highly contentious divorce. I have the utmost faith and confidence that he will succeed in getting me the most favorable and positive result at the end of this litigation. Having Dave guiding and representing me was the best decision I made. I would highly recommend David T. O'Sullivan to anyone looking for an attorney, especiallly a divorce attorney.
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Posted by Anina | November 14, 2013
Bankruptcy isnt easy, but he made it easier for me.
Mr. O'Sullivan was a huge help through my case. I know that would be his job, however he made me feel secure through the process, always kept me up to date and was a terrific guide through it all. I was scared and helpless, and he helped me through a difficult time, when I wasn't sure how to get out of my debt.I couldn't have done it without him. Thank you.
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Posted by Current client, post-litigation | November 11, 2013
Skilled litigator
It took five years and as many lawyers to find Mr. O’Sullivan. From what he has accomplished since with grace, truth, and shown me is legally possible since placing him on retainer, I can only surmise that a greater power thought it important for me to experience the narcissistic maniacal and lip service attorneys rivaling the ex attorney spouse that came before him. He is respectful of where I have come from, he does not look down on me for staying when I should have left, he understands the emotional roller coaster and deception of which the children and I continue to live with, and is more than willing and able to confront adversity while protecting me from blows intended to harm. His truths are brazen and lack sugar coating, a quality I admire and more of us need to hear in place of promises never intended or possible. He has extensive and astute financial experience from which to draw from for advise whether real estate, personal finances, or the need for planning as example, and savvy enough to know when it is best to refer out to his extensive circle of trusted professional resources. He is willing to admit when things confound and search for the answer within the law while utilizing his capable, client supportive, and outstanding staff to prepare. He is accessible, chivalrous (loyal, considerate, courteous), and honest to a fault (understanding that the truth often hurts, needs to be said, and provided without maliciousness or implied fault). He gets the demoralization, discouragement, and deceptiveness that accompanies divorce and its all-encompassing co-morbidities [sic] and is willing to take a stand backed by the full knowledge of the law. He counsels with and seeks the truth. As a corporate attorney’s wife for over thirty years, I am very confident in recommending Mr. O’Sullivan in his specified areas of expertise. Sadly, from those years and literally hundreds of rolodex attorneys known both professionally and personally, there is only one other officer of the court for which I have such confidence (Estate Law, Indiana). In choosing Mr. O’Sullivan to represent your interests, you will find a highly qualified professional providing solid advice, alternatives when possible, and a knack for reading people. That last quality should never be underestimated in contentious litigation. He is not a therapist nor should he be, but is fully prepared with the necessary intellectual and social skills to perform his job and will give you the best of his ability. I hope that as a potential client you will do him the same justice in providing honest disclosure in return.-
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Posted by Kevin | November 11, 2013
Getting a Divorce? Hire David immediately !!!
David guided me through a very difficult time in my life during a long drawn out divorce process... I am proud to say that I am David's second longest client! David has become a very good friend and I look forward to continuing a great working/friend relationship.
Posted by John | November 6, 2013
Divorce with a positive result!
Getting a divorced is a process that can be very emotional and financially draining. To me, finding a law firm that is trust worthy , professional, a firm that can simplify the process so there clients can understand and know what to expect as they move through this difficult time in there lives is so important. To the Law firm of David T O'Sullivan, many thanks!!!!
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Posted by Julie | November 6, 2013
Help, when I didn't know what the next step should be
I needed to seek help from Dave and Rebecca after losing overtime and taking a big pay cut, for the 1st time in 16 years, I wasn't sure what I was going to do, how was I going to pay rent and other bills with such a steep loss in income? I had no real knowledge on how bankruptcy worked and it was something I never thought I would need/have to do(wasn't feeling like my proudest moment) I was constantly worried about bills/money and knew that I needed to talk to someone! Immediately after meeting Dave and talking to him, his confidence and knowledge with bankruptcy really made me feel comfortable and confident that he was a good fit to be my lawyer, he could tell I was upset and spoke to me in a way that made me feel better and he really put my mind at ease, he explained everything to me in detail, answered any and all of my questions and even talked to my mom and educated her in how the process would take place(which was going above and beyond) I left his office feeling so much better then I did when I first went to see him! All of his staff are friendly and I consider Dave and Rebecca to be answers to my prayers! The bankruptcy process was very intimidating and scary to me, but being able to talk and email with Rebecca and Dave, the process went very smooth! Thank god for people like Dave and Rebecca to help people like me, not only did they help with my bankruptcy case, but they spoke to me and treated me like a human being, never judged me and with bankruptcy not being an easy decision(pride was hurt) that is a very important thing! Rebecca and Dave truly came to my rescue! I would highly recommend Dave and Rebecca to anyone needing any type of assistance where a lawyer is needed...please do yourself a favor and make an appointment to see them! You will not be sorry!!
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Posted by Amy | November 5, 2013
David T O'Sullivan recently represented me in a divorce case that had a complicated international component. He is well versed not only in NJ matrimonial law, but is ready and willing to take on cases that originate elsewhere. He is very responsive by phone and email which has been outstandingly helpful. It is comforting to know David is in your corner, and I highly recommend his services.
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Posted by Mary | June 5, 2013
Help during stress
Your experience with a lawyer can only be based on what you are willing to put into it. David will give you all the information that you need to make the choices that best suit your case. He will answer any questions that you have. He will give you very honest feedback whether it is what you wanted to hear or expected to hear. That is exactly what I was paying for and I am grateful. l would highly recommend David to my friends.
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Posted by Janice | January 2, 2013
Mr. O'Sullivan is an excellent attorney. He helped me with my divorce, which was not easy. He was always available via phone or email. He even gave me his cell in case I needed him after hours. He was always up-front with me, always truthful. He would even call me just to see how I was doing. If you are in need of an ‘EXCELLENT” divorce attorney, I recommend you give Mr. O'Sullivan a call. You’ll be happy you did… Thank you David, I will always be greatful…..
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Posted by Victoria | October 22, 2012
Outstanding lawyer and friend
David is truly an amazing lawyer and person. Not only has he gone out of his way to help me but also genuinely cared about my case and what I was going through. When confronted with difficulties in our lives it is so important to have somebody helping you that gives you the emotional support as well as the professional help that is needed and David has certainly displayed that behavior to me. He is always there when you need him and returns calls right away, which is key when dealing with urgent situations when they arise. I consider David not only my lawyer but my friend.
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Posted by anonymous | April 28, 2011
Skilled Council
I have needed David's services on two occassions and was completely satisfied both times around. He is both skilled at his trade and quite personable. I would easily recommend him without a moment's hesitation.
Posted by Marta | February 21, 2011
David O' Sullivan is an Outstanding Attorney!
David O'Sullivan was completely honest and upfront with us. I was impressed with his knowledge and excitement of the law. David always performed his tasks diligently, and we were very pleased with his responsiveness, and the above and beyond effort he contributed to our case. This attorney will work for you!!
Posted by Stacey | January 14, 2011
Absolutely surpassed my expectations . . .
I am not sure where to begin but from the moment I called and his instant response to my needs and concerns I had piece of mind. My son and I are in a better place now with support and health insurance and for that as a single mom I am at peace for the welfare of my son. We are entirely grateful to Dave for his swift action to resolve the matter and follow through on the promises he made to me. I could not recommend a better lawyer - he makes you realize that there are attorneys that are great guys! Should you require any additional information about my experience or like to contact please do so. Thanks Dave!
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Posted by anonymous | February 2, 2013
Not if your a father
I would not recommend this lawyer for fathers seeking help. He is a basic lawyer, will take your retainer, but not fight hard for you, or your rights. When we finally came close to possibly a positive ruling , he wanted another $4000 retainer. Was promised he would take care of my situation with the first retainer! We need more lawyers who will fight for fathers and their children! I had no more money to fight, so I never had resolution, and ultimately my children suffered.
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Response from David O'Sullivan February 6, 2013
We represent fathers and mothers equally and every member of my staff works tirelessly on their behalf. I remember this client well; He not want to pay for our services and wanted us to work for free after his retainer was exhausted. We do not treat mothers and fathers differently, and the fact that he is a "father" has no bearing on our fees. We are no different than any other working professional; we expect, and deserve, to be paid for the quality legal services that we provide, and we do not make promises regarding how long or how much litigation will cost. Our focus is to provide our clients with the highest level of legal representation at the lowest possible cost. We truly appreciate the trust that our clients place in us, and we honor that trust daily by providing each and every client with high quality legal representation throughout the State of New Jersey.
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Posted by anonymous | October 4, 2021
This review is from a person who hired this attorney.
| Hired Attorney
Divorce attorney
Made math errors while having all the detail that cost me thousands of dollars. Promised to meet me for the closing and never called. Then shared that the Judge made his decision and the closing wasn't important. I watched the other side press an outstanding closing and not leaving a stone unturned. He told me the Judge doesn't like you. Several attorneys later explained it had to do with the delivery and the closing is as important, LAZY!
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  • Free Consultation 60 minutes
Payment methods
Cash, Check, Credit Card


AVVO RATING 9.2 (Superb)

Work Experience

  • Owner
  • O'Sullivan Law Group, LLC
  • 2014 - Present
  • Owner
  • Law Office of David T. O'Sullivan, LLC
  • 2010 - 2014
  • Managing Partner
  • Simeone & O'Sullivan, LLP
  • 2006 - 2010
  • Vice President Coporate Services
  • Cushman & Wakefield
  • 2005 - 2006
  • Sr. Vice President - Corporate Services
  • Trammell Crow Company
  • 2002 - 2006
  • Director - Advisory Services
  • Ernst & Young
  • 1999 - 2002
  • Director - Corporate Real Estate
  • AlliedSignal, Inc (Honeywell)
  • 1993 - 1999
  • Judicial Clerk to Hon. Katherine Dupuis, J.S.C.
  • Superior Court of New Jersey
  • 1993 - 1993
  • Judicial Clerk to Hon. David G. Lucas, J.S.C.
  • Superior Court of New Jersey
  • 1992 - 1993
View all work experience


  • Seton Hall University
  • MBA - Master of Business Administration
  • 1995
  • Seton Hall University
  • JD - Juris Doctor
  • 1992
  • Boston Uninversity
  • BS - Bachelor of Science
  • 1985


  • New Jersey State Bar Association
  • Member
  • 2006 - Present
  • Morris County Bar Association
  • Member
  • 2006 - Present
  • New Jersey State Bar Association, Family Law Section
  • Member
  • 2006 - Present
  • Jersey Battered Women's Service
  • Pro Bono Attorney
  • 2006 - Present
  • Battered Women's Legal Advocacy Project
  • Volunteer Attorney
  • 2006 - Present
  • Morris County Bar Association, Family Law Section
  • Member
  • 2006 - Present
View all associations

Languages Spoken

  • English

Honors and Awards

  • Super Lawyers Rising Star
  • Thomson Reuters
  • 2016
  • Super Lawyer's Rising Star
  • Thomson Reuters
  • 2015

Speaking Engagements

  • NJ Divorce Essentials Webinar
  • Essentials of Divorce in NJ
  • 2015
  • Understanding Divorce in New Jersey
  • Divorce in New Jersey
  • 2009
View all speaking engagements

Attorney endorsements

Received (5)
Given (6)
Endorse David
Divorce and separation Attorney | May 17
Relationship: Opposing Counsel on matter
"David is a highly skilled and experienced family law attorney who advocates for his clients and yet is a pleasure to work with as an adversary."
Family Attorney | Oct 18
Relationship: Opposing Counsel on matter
"David is a strong advocate for his clients. He is knowledgeable and aggressive, but tries to find a reasonable solution when possible."
Divorce and separation Attorney | Feb 16
Relationship: Opposing Counsel on matter
"David and I were adversaries on a very contentious and financially complex divorce. David was incredibly proficient at the nuances of determing the value of a business as well as cash flow of the litigants. It was a pleasure working with an attorney who understood the complex financial and tax issues presented in high net worth divorce. David is agressive but not unreasonable which is a valuable combination in the divorce arena."
Unknown Attorney | Apr 01
Relationship: Fellow lawyer in community
"Top-notch attorney. Highly respected in the legal community."
Domestic violence Attorney | Jan 19
Relationship: Opposing Counsel on matter
"I endorse this lawyer. David is a zealous advocate and a gentleman."