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John W. Dennehy

Litigation Attorney at Nashua, NH

3.7   3 reviews
  • State Years
    New Hampshire - NH 19 years
    Massachusetts - MA 20 years
  • Licensed for 19 years
    State NH
    Acquired 2004
    Active No misconduct found
  • Licensed for 20 years
    State MA
    Acquired 2003
    Active No misconduct found

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

About John

Learn John’s areas of practice.

Practice areas
  1. Litigation
    Litigation & Appeals: Civil Litigation, Construction Litigation, and Business Disputes.

    21 years, 1,500 cases

  2. Business
    Litigation and Counseling services for businesses and business owners, including partnership disputes, hedge fund and self directed IRA matters, contract disputes, sales disputes, and employment matters.

    21 years, 300 cases

  3. Construction and development
    Design & Construction Law: Litigation and Counseling services for project owners, contractors, sub-contractors, and design professionals. All aspects of construction related matters, from contract development and negotiations, to loss prevention during projects, and handling disputes through mediation, arbitration, and litigation.

    21 years, 1,000 cases

  4. Contracts and agreements
    Review and drafting contracts for businesses and individuals, include sale of business agreements, license and franchise agreements, construction contracts, non-compete and confidentiality agreements, and employment contracts.

    21 years, 250 cases

  5. Corporate and incorporation
    Counseling businesses and individuals in all aspects of business formation considerations, including Partnerships, Corporations, Limited Liability Companies, and Professional Corporations.

    21 years, 50 cases

Mr. Dennehy is the Managing Partner of a boutique law firm providing Litigation and Counseling to businesses and individuals. John has handled in matters in ME, NH, VT, MA, RI, NY, NJ, MD, GA, LA, NA, WI, WA, and CA. He has successfully handled numerous cases in New Hampshire and Massachusetts through conclusion at trial, as well as administrative hearings and arbitration proceedings.

Specialties: Business Litigation, Design & Construction Law, Corporate Law, Insurance Law, and Employment Practices.

John has represented clients in complex business disputes, involving self-directed IRAs, hedge funds, copyright and trademark violations, partnership disputes, as well as trade secret and commercial contract disputes. He has represented architects, engineers, surveyors, owners, builders, attorneys, and real estate brokers in litigation matters. John has handled a wide range of disputes involving high rise buildings, hospitals and laboratories, office buildings, college and university buildings, preparatory and public school buildings, museums, churches, manufacturing plants and processing facilities, water treatment facilities, roads and bridges, as well as tax issues and real estate transfers.   

And he often represents individuals in matters requiring strong advocacy. He engages in high exposure personal injury matters including wrongful death, traumatic brain injury, quadriplegia, amputation, and disfigurement, as well as Criminal Defense.

He graduated from UNC Wilmington (BA) and Suffolk University Law School (JD).  Previously, Mr. Dennehy was a Litigation Partner at Donovan Hatem LLP, and counsel at Devine Millimet & Branch. He also worked in the insurance industry for Safeco Insurance Companies and Commerce Insurance Group, and served in the U. S. Marines.


127 Main Street, Suite 1
Nashua, NH, 03060
265 Franklin St, Ste 1702
Boston, MA, 02110
15 Cambridge Road
Hampstead, NH, 03841
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3.7 / 5.0
  3 customer reviews
5 Star
4 Star
3 Star
2 Star
1 Star
Posted by Naqi Ur-Rahman | December 4, 2016
This review is from a potential client who consulted with this attorney.
| Consulted Attorney
Amazing Lawyer
John clarified all my concerns and helped me understand my situation in a well mannered and polite way. He is extremely helpful and non-judgmental at all. If anyone ever needed any consultation or a lawyer I would contact him right away without any hesitation.
Posted by Lisa | August 28, 2016
This review is from a potential client who consulted with this attorney.
| Consulted Attorney
Loan/Gift Question
John promptly answered my questions concerning receiving loan or gift money. He was professional, direct and quite helpful. I plan to keep John's information if I am ever in need of hiring a lawyer.
Posted by Nate | May 14, 2019
This review is from a person who hired this attorney.
| Hired Attorney
Never followed through
John Dennehy is quick to take your money but terrible at following through on the services you are paying for. I hired him to help me develop contracts for my business. After numerous delays, including a month with literally zero contact, he finally delivered plain unaltered boilerplate contracts. He did not include any of the details or clauses I had requested, and in fact left in quite a bit of junk that does not apply to my business. This was a huge waste of my money.
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  • Hourly Rates $ 225-365 per hour
Payment methods
Cash, Check, Credit Card


AVVO RATING 7.1 (Very Good)

Work Experience

  • Managing Partner
  • 2014 - Present
  • Litigation Partner
  • Donovan Hatem LLP
  • 2007 - 2014
  • Litigation Associate
  • Devine Millimet & Branch
  • 2004 - 2006
  • Litigation Associate
  • O'Connor & Associates, LLC
  • 2003 - 2004
  • Claims Management
  • Commerce Group, Inc.
  • 1998 - 2003
  • Claims Adjuster
  • Safeco Insurance Company
  • 1994 - 1998
View all work experience


  • Suffolk University Law School
  • JD - Juris Doctor
  • 2003
  • University of North Carolina Wilmington
  • BA - Bachelor of Arts
  • 1994
  • Pinkerton Academy
  • Diploma
  • 1986

Sample of Legal Cases

  • Plaintiff v. Bank
  • Defense Verdict
  • Land Development Company v. NH City
  • Defense Verdict
  • Plaintiff v. NH College
  • Defense Verdict
View all legal cases


  • Rockingham County Bar Association
  • Member
  • 2014 - Present
  • Defense Research Institute
  • Member
  • 2011 - Present
  • Boston Bar Association
  • Member
  • 2010 - Present
  • New Hampshire Bar Association
  • Member
  • 2004 - Present
  • Massachusetts Bar Association
  • Member
  • 2003 - Present
View all associations

Languages Spoken

  • English

Honors and Awards

  • CPCU, Commercial Concentration
  • American Institute of Chartered Property Casualty Underwriters
  • 2002
  • Claims Production Award
  • Safeco Insurance Companies
  • 1997
  • Associate in Claims
  • Insurance Institute of America
  • 1996


  • Design & Construction Reporter republished by ASCE- Member Insurance
  • Design Professionals Dismissed from Two New Hampshire Lawsuits
  • 2009
  • Design & Constrcution Reporter
  • Indiana Appeals Court Holds Economic Loss Doctrine Bars Negligence Claims Against Professionals
  • 2009
  • The Design & Constrcution Reporter republished by SullivanKreiss Executive Search Blog
  • Massachusetts Court RulesDesign Team is Not Responsible for Contractor's Failure to Perform Work
  • 2008
  • American Bar Association's Manual on Product Liabililty Warnings
  • American Bar Association's Manual on Product Liability- New Hampshire Section
  • 2006
View all publications

Speaking Engagements

Attorney endorsements

Received (2)
Given (1)
Endorse John
Criminal defense Attorney | Feb 26
Relationship: Fellow lawyer in community
"Glad to endorse this attorney. He provides excellent answers and advice to client questions. Zealously represents his clients interests."
Litigation Attorney | Jun 14
Relationship: Fellow lawyer in community
"I endorse this lawyer."