Free Consultation
$0 first 6 minutes
John primarily handles state court litigation and concentrates his practice in the areas of real estate law (transactional and litigation), estate planning and probate (decedent’s estates and guardianships), small business law, and civil litigation. John practices throughout Cook, DuPage, Lake and Will counties.
John graduated from John Carroll University with a Bachelor of Arts in Communications (2005) and graduated with a Juris Doctorate cum laude from the Western Michigan Thomas M. Cooley Law School (2008). Prior to working at Diaz Anselmo Lindberg, P.A., John was an associate attorney with Spain, Spain & Varnet, P.C., a senior associate attorney at Alicja M. Sroka & Associates P.C., and operated his own solo practice.
John is a general member of the Chicago Bar Association (2009-present), the Illinois State Bar Association (2009-present), the DuPage County Bar Association (2016-present), and the American Bar Association (2009-present).
He serves as an appointed member of the Illinois State Bar Association’s Standing Committee on Delivery of Legal Services (2016-present) and the Illinois State Bar Association’s Standing Committee on Judicial Evaluations – Cook County (2017-present).
He has spoken at several events, served as a competition judge for a number of past American Bar Association and Chicago Bar Association student competitions, and has previously volunteered with the Chicago Bar Association’s Juvenile Justice Mentoring Initiative and Wills for Heroes programs.
John lives in Wheaton with his wife and two children.
8
Practice Areas
16 years
16 years
16 years
16 years
Free Consultation
$0 first 6 minutes
$ 175-375 per hour
Quickly connect with top attorneys through our legal directory to get help with your legal issue.
Chat with a live agent who can match you with the right attorney for your legal needs.
Chat withState: Illinois
Acquired: 2009
No misconduct found
1771 West Diehl Road, Suite 120, Naperville, IL, 60563
Showing 1 - 5 of 72 client reviews from Avvo
Posted by Anthony | September 10, 2025 | Consulted Attorney
I have been working with John Brennock and his staff for 5 years for the purchases of 2 commercial multi-unit properties in Wicker Park, as well as a 3-flat in Wrigleyville. I have trusted all my closings with him, as well as an easement issue I had with a neighbor. He walked me through several pos...
Posted by anonymous | September 6, 2025 | Hired Attorney
Super helpful. Prompt. Answered all of my questions. Even on a friday night!
Posted by Ken | August 31, 2025 | Hired Attorney
John was my attorney for my purchase of a multi-unit building. John was very responsive to my questions, gave me great advice, and solved problems that came up due to inspections / appraisals and an international seller. I recommend John to anyone looking for an excellent real estate attorney.
Posted by Jeanette | August 31, 2025 | Hired Attorney
I was lucky enough to be referred to John Brennock when I was looking for an attorney to handle my real estate purchase. From our first phone consultation through the inspection, the attorney review, the closing itself, and concerns after the closing, John's professionalism, courtesy, good humor ...
Posted by Shideh | July 11, 2025 | Hired Attorney
I had an outstanding experience with Diaz Anselmo Law Firm while selling my house and buying my condo. Attorney John Brennock and paralegal Anne Baker were exceptional, ensuring a successful and seamless closing. I would not hesitate to work with them again and highly recommend their services for rea...
"I endorse John. He is a passionate and zealous advocate for his clients and an absolute professional to work with."
"Mr. Brennock is an excellent attorney with an excellent track record. When it comes to representation in the greater Chicago area, you cannot go wrong using Mr. Brennock's exceptional services. Do not let your rights be handled by anyone else -- Mr. Brennock is the right stop for you."
"I find Mr. Brennock to be a highly reputable and reliable attorney who is knowledgeable, capable and compassionate towards his clients. Anyone needing legal advice should turn to John Brennock. I endorse this lawyer."
"I endorse this lawyer. John tutored me years ago in law school, and he always had a thorough command of the various areas of law. We have talked often since then, and he has given me valuable advice on how to run my practice and help clients. If you live near Chicago and have a problem that John can help you with, I unquestionably recommend a call to John."
"I endorse this lawyer. Attorney Brennock is an outstanding attorney with an excpeptional reputation. He is a strong and zealous advocate for his clients and a credit to the legal profession."
"I endorse this lawyer. He is bright, knows the law well, has a great temperment yet is an excellent advocate for his clients. He has a strong work ethic and always quotes the most reasonable fees. I know he has many satisfied clients."
"J.E. Brennock is an aggressive, insightful and smart lawyer who provides valuable service and assistance to his clientele. Most importantly he is a person who can be trusted and zealously protects his client's interests. I strongly recommend him to be your counsel. Carlton R. Marcyan Attorney/CPA/CFP"
Unknown lawyer
Foreclosure lawyer
Litigation lawyer
Criminal defense lawyer
Landlord or tenant lawyer
2015
Client's Choice Award - Landlord & Tenant Law, Avvo
2014
Client's Choice Award - Landlord & Tenant Law, Avvo
2013
Client's Choice Award - Landlord & Tenant Law, Avvo
2012
Clients' Choice Award - Landlord & Tenant Law, Avvo
2008
The Eugene S. Quigley Delta Theta Phi Scholarship Award., Delta Theta Phi Law Fraternity, Power Senate
2023 - Present
Senior Associate Attorney, Diaz Anselmo & Associates P.A.
2021 - 2023
Associate Attorney, Diaz Anselmo & Associates P.A.
2020 - 2021
Principal, Law Offices of John E. Brennock
2019 - 2020
Associate Attorney, Spain, Spain & Varnet, PC
2015 - 2019
Senior Associate Attorney, Alicja M. Sroka & Associates, P.C.
2009 - 2015
Principal, Law Offices of John E. Brennock
2008 - 2008
Legal Intern, Glassen Rhead McLean Campbell & Schumacher
2008 - 2008
Student Attorney, Washtenaw Public Defender Clinic
2017 - Present
Illinois State Bar AssociationMember - Judicial Evaluation Committee (Cook County)
2016 - Present
DuPage County Bar AssociationMember
2016 - Present
Illinois State Bar AssociationMember - Standing Committee on Delivery of Legal Services
2011 - Present
First American TitleAttorney Title Agent
2011 - Present
Chicago TitleAttorney Title Agent
2009 - Present
American Bar AssociationMember
2009 - Present
Chicago Bar AssociationMember
2009 - Present
Illinois State Bar AssociationMember
Appellate court affirmed dismissal of claims against Defendant/Client
Settled - Tenant received $5,550.00
Settled - Tenant received $4,314.50
2008
JD - Juris Doctor
2006
BA - Bachelor of Arts
2024
Title 101 and 2024 Title Market Trends: What REALTORS Need to Know
2024
Risk Mitigation, Protecting Your Interests and Getting the Deal Closed: Your Attorney's Role in the Real Estate Transaction
2019
2017
Arbitration Competition - Judge
2015
2015
2014
Moot Court - Appellate Judge
2014
2017
English
Legal Answers
Legal Guides
If tenants left apartment unclean but not filthy or damaged may landlord retain partial deposit for cleaning costs?
05 Feb 2014
Roofers damaged my AC Unit and Condo board won't do anything about it
12 Jun 2013
If i move out and my roommate resigns the lease with a friend can my landlord hold onto my security deposit until she moves out
04 Jun 2013
How to break a residential lease in Chicago (where the CRLTO applies), Part 3 of 3.
20 Mar 2011
How to break a residential lease in Chicago (where the CRLTO applies), Part 2 of 3.
20 Mar 2011
How to break a residential lease in Chicago (where the CRLTO applies), Part 1 of 3.
20 Mar 2011