Trusted Counsel in Princeton, NJ
We keep the interests of our clients first in everything we do
For three generations, the McCarthy Law Firm has been helping people resolve legal issues. I will devote my best efforts to continuing that tradition.
Our service areas
Estate Planning
An estate planning attorney (or estate lawyer) helps individuals and families prepare for the transfer of assets and responsibilities.
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Estate Administration
An estate administration attorney helps settle a person’s affairs after their death by guiding the executor or personal representative.
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Real Estate
As real estate attorneys we specializes in legal matters related to buying, selling, leasing, or managing property.
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John F. (“Jack”) McCarthy III
Attorney
A lifelong Princeton resident and third-generation Princeton attorney, John F. (“Jack”) McCarthy, III has practiced law in Princeton for more than 50 years, with an emphasis in estate planning, probate, real estate, and business law, representing closely held businesses and individuals in commercial transactions and estate matters.
Jack McCarthy graduated from Princeton University with highest honors in history, winning the Phelps Prize for the best European History thesis and also winning a National Science Foundation grant. He was a goalkeeper on Princeton’s varsity soccer team for two years and a member of the university’s Ivy Club.
After receiving his J.D. from The University of Pennsylvania Law School, where he was a member of the Sharswood Law Club, Jack McCarthy practiced law with a New Jersey firm in Newark and then served as an Assistant Deputy Public Advocate for the N.J. Division of Rate Counsel. He was a director and shareholder of a Princeton law firm for more than 25 years before joining the McCarthy Law Firm with his father, John F. McCarthy, Jr.
- University of Pennsylvania, J.D., 1973
- Princeton University, B.A. summa cum laude, 1969
- Lawrenceville School, 1965
- Irish Legal 100 (top 100 Irish-American attorney and judge nominated by the Irish Voice in 2009)
- 2000 Mercer County Friendly Sons of St. Patrick Irish-American of the Year
- New Jersey
- Florida
- Qualified Mediator
Ivette J. Castano
Paralegal/Office Manager
Ivette J. Castano is a dedicated and bilingual legal professional with over 30 years of experience supporting attorneys and clients in estate planning, probate, real estate, and litigation. Known for her strong work ethic, attention to detail, and calm under pressure, Ivette brings both precision and compassion to her work. She is fluent in English and Spanish and is a commissioned Notary Public.
Ivette currently serves as a Paralegal and Office Manager at McCarthy Law Firm, where she was welcomed back in 2025 due to her strong client relationships and reliable performance. She supports a wide range of legal matters while also managing daily firm operations.
She earned her Associate in Applied Science degree in Paralegal Studies, graduating with Highest Honors, and was inducted into Phi Theta Kappa. Ivette is highly proficient in a variety of legal and office software and is frequently recognized for her initiative, professionalism, and ability to support attorneys and clients with care and efficiency.
When Ivette is not in the office, she enjoys traveling around the world and spending time with her family and friends.
Our history
Established - Experienced - Trusted
The McCarthy Law Firm is a Princeton institution.
John F. McCarthy, Sr. founded the McCarthy Law Firm in 1927. Previously, he had worked in Princeton as a butcher, and a train conductor for the Johnson Trolley that ran between Princeton and Trenton. Princeton was a small village then and, like many other town residents, Mr. McCarthy became acquainted with then-Professor Woodrow Wilson and attended Wilson's 1912 and 1916 presidential inaugurations. Inspired and encouraged by Princeton’s eminently successful son, Mr. McCarthy worked his day jobs and attended Newark Law School (now Rutgers) at night. Passing the bar in 1927, he worked out of his house on Charlton Street, opposite St. Paul Church. Starting a law practice in the middle of the Great Depression meant many clients paid their legal bills in kind; eggs, chickens, even home repairs.
His son, John F. (“Jack”) McCarthy, Jr., joined the firm in 1948. A graduate of Princeton High School (at age 16), the Hun School, and Princeton University’s Class of 1943 (with honors), he played basketball, captained the baseball team and was voted “Most Popular” and “Best Sense of Humor”. As a left-handed first baseman, he hit a 400-foot home run over the right field fence at Cornell. (Columbia’s Lou Gehrig was, reputedly, the only other player to accomplish that feat.)
Commissioned as an officer in the field artillery, he landed in Normandy on D-Day plus 2 and earned a Purple Heart for sustaining a mortar round in his shoulder and a Bronze Star for bravery in rescuing five enlisted men pinned under German fire. He was discharged in 1945 and graduated from the University of Pennsylvania Law School in 1948.
After his father died in 1954 Jack McCarthy Jr. built the law to one of the most successful in Princeton. He served as Princeton Borough attorney in the late the 1950’s under Mayor Raymond Male and argued several cases in the New Jersey Supreme Court. He expanded the firm, added partners and moved to an entire building at 6-8 Charlton Street in the 1960’s. The firm stayed at that location until 1987. Jack McCarthy Jr. served as one of four members, later chairman, of the New Jersey State Commission of Investigation from 1971 to 1974.
Jack McCarthy Jr.’s life and legal career are chronicled in the book Of Town and Gown: The Life and Times of John F. McCarthy Jr. (1921-2012), with an introduction by John McPhee, which traces his journey from early beginnings to his work as a respected advocate and advisor. The biography offers an in-depth look at the personal and professional experiences that shaped his path. It is available on Amazon.
Jack McCarthy III joined the firm in 1976. Two Superior Court judges, Theodore Tams and Coleman T. Brennan, were associated with the office in the 1970’s. Former Governor William T. Cahill was with the firm from 1974 to 1978, when it was known as Cahill, McCarthy and Hicks. John P. Sheridan, Jr., former Commissioner of the Department of Transportation, was with the firm from 1974 to 1981, as was now-retired Superior Court Judge F. Patrick McManimon.
Jack McCarthy Jr. and Jack McCarthy III moved their offices to 353 Nassau Street in 2005. Jack McCarthy Jr. died in 2013. In 2019, Jack McCarthy III moved his office to 707 State Road.