The Hometown Lawyers Who Truly Care

Our clients are our neighbors, friends, and colleagues, and we’re honored and humbled that so many of them have chosen us to represent them during the most exciting or most difficult times in their lives. 

When my wife was diagnosed with early-onset Alzheimer’s we knew had to make objective and sensitive decisions about our future and estate, and quickly. Mark has been a dear friend for over 30 years, and he is a reliable and trustworthy attorney. I wouldn’t trust anyone else to assist my family in our time of need.
— Mike F.

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What Sets Us Apart

Our close-knit, multi-generational team treats each client’s case with the same care as if they were a good friend or trusted neighbor - and many of them are. 

Our clients value us for our integrity and willingness to fight for their best interests every step of the way. Whether it’s an exciting occasion like negotiating contracts for a new home or a difficult one like litigating a personal injury case where a client was severely injured, Slevin and Slevin, Esqs. will be your fiercest advocate. 


At every turn I felt that Slevin & Slevin, Esqs. had my best interest at heart.
— Kathryn A.


Our Story

A family by blood, a law firm by choice.

As children, Mark and Michael Slevin did everything together: in fact, you couldn’t throw a stone in Stony Brook village without hitting one of the six Slevin boys during the late 70’s and 80’s. 

They’ve come a long way from digging up clams on Sand Street Beach, but their roots run deep.

Graduating law school only a couple of years apart, Mark and Michael were at two different stages of life when they were admitted to the bar and began practicing law. Mark was married, working a full-time job in the insurance industry, and growing his young family. Michael became an associate in a fast-paced and nationally recognized litigation firm living the hustle and bustle New York City life.

Approximately a decade later, when they each found themselves looking to break out on their own, it didn’t take long for a business plan to develop, and Slevin & Slevin, Esqs. was born.

A few years later, Mark’s son Aidan was working in a non-profit sector job when it lost its funding in the great financial budget deficit of 2018, and Aidan took the opportunity to go back to his roots, too. Now, the trio work together, building stronger relationships between themselves, their clients, and community every day.