Justice Ralph Costello was born in Jamaica, Queens and moved to West Babylon in 1951 with his parents, his younger brother Frank and sister Margaret, now Margaret Bonventre. He was a member of the Class of 1959. As a student, he played football and was an early member of the Marching Band and the school Dance Band.

After graduation, Justice Costello attended Stony Brook University and St. John’s University Law School, earning his law degree in 1967. Soon after his admission to the Bar, he joined the Legal Aid Society of Suffolk County and for the next 22 years, worked in both the civil and criminal branches representing clients in all courts in Suffolk County and before various boards and agencies. Through the years, Justice Costello rose to the position of Chief Assistant Attorney of the Legal Aid Society of Suffolk.

As the designated representative of the Legal Aid Society, Justice Costello served on various government advisory panels including the County Executives Public Safety Advisory Committee formed by the then County Executive John V.N. Klein. Also as a voting member of the Suffolk County Criminal Justice Coordinating Counsel reviewing and passing on various State and Federal funding applications, he sat on panels such as the Jail Overcrowding Committee and the Community Service Board of Advisors.

Justice Costello was a founding member of the Suffolk County Community Service Program, sponsored by the American Red Cross and he was a member of its board from 1980 through the early 1990s when he was elected to the District Court bench from Babylon Township. After serving five years of his six-year term in the District Court, he was elected to Supreme Court Justice presiding over civil trials.

Justice Costello shared his experience with his fellow community lawyers and judges through lectures under the umbrella of The Suffolk Academy of Law of the Bar Association and his participation on various boards and committees, such as the Suffolk County Bar Association Board of Directors, The Suffolk County Criminal Bar Association, The Columbian Lawyers Association and numerous committees of specialized interest of the associations.