Thomas Demetrios Lambros (born February 4, 1930) is a former United States federal judge.
Lambros was born in Ashtabula, Ohio. He was the son of Greek immigrants Demetrios P. and Panagoula (Bellios) Lambros, and was the youngest of five brothers. He graduated from Ashtabula High School in 1948 and attended Fairmont State College in West Virginia, majoring in pre-law. In 1952 at age 22, he received his LL.B. from Cleveland-Marshall College of Law, having accelerated his studies by attending summer and night classes at the Ohio State University Moritz College of Law and Case Western Reserve University School of Law.
Lambros was a claims representative for the Buckeye Union Casualty Company in Akron, Ohio from 1952 to 1953 while in law school. In 1991, he was awarded an honorary doctor of law (LLD) degree from Capital University Law School in Columbus, Ohio.
After being admitted to the Ohio bar, Lambros joined the United States Army, serving as a law clerk in the United States Army Judge Advocate General's Corps from 1954 to 1956.
Lambros was in private practice of law in Ashtabula, Ohio from 1956 to 1961 as a trial lawyer in the firm of Lambros & Lambros. In 1960, he was elected at the age of 30 to the Ashtabula County]] Court of Common Pleas. He was reelected in 1966 without opposition. As a common pleas judge, he established a voluntary public defender program to provide free counsel to indigent defendants, as well as a mandatory domestic relations reconciliation program.