Thomas D. Finney Jr., 52, a Washington lawyer who had been associated with a number of top political figures, died Monday at his home in Bethesda.

He suffered from amyotrophic lateral sclerosis, better known as Lou Gehrig's disease. He was a member of the prestigious law firm of Clifford, Glass, McIlwain and Finney, which he had joined in 1963. He had nto practiced law actively, however, for the last eight months.

Mr. Finney came to Washington in 1957 as administrative assistant to Sen. A.S. Mike Monroney (D-Okia.), remaining in that position until 1963.

He built a reputation as a politican and legislative strategists, and during this period was a major author of the Federal Aviation Act.

In 1960, Mr. Finney worked with Adlai E. Stevenson and organized the remarkable gallery demonstration for Stevenson at the Democratic converntion that year.

Later, the victor, Ptesident John F. KEnnedy, borrowed Mr. Finney to work on the Trade Expansion Act, which Mr. Kennedy considered one of his most outstanding achievements. Mr. Finney advised the president as a member of his Task Force on Foreign Policy, as deputy special assistant to the president for Foreign Trade Policy and as director of congressional liaison for the Trade Expansion Act.

in 1964, President Lyndons B. Johnson asked Mr. Finney to go to Mississippi with Allen Dulles when disorders develop there involving the registration of black voters.

Mr. Finney recommended the FBI agent s be sent to the rural counties of Mississippi to monitor the registration. That same year he was special counsel to the credentials committee at the Democratic National Covention in Atlantic City.

Mr. Finney was credited with being among the key figures who helped solve the politically explosive dispute over which a delegation from Mississippi would be recognized.

In 1968, Mr. Finney took a leave of absence from his law firm to work in the presidential campaign of Eugene McCarthy. He was considered to have the most political expertise in the organization.

Mr. Finney directed McCarthy's primary victory over Robert Kennedy in Oregon, visited the Kennedy family was assassinated and remained the McCarthy liason with Kennedy's followers.

Born in Idabel, Okla., Mr. Finney served as a Navy officer toward the end of World War II and then earned a bachelor's degree in political science from the University of Oklahoma where he received a law degree in 1948.

He practised in Idabel for three years with his father, the late Thomas D. Finney, a pioneer trial lawyer. He then served with the Central Intelligence Agency in Copenhagen, Denmark, from 1952 to 1955.

Before joining Sen. Monroney in Washington, Mr. Finney was in private law practise in Oklahoma City.

He was a director of Continental Airlines and general counsel to the Proprietory Association. He was a trustee of the Citizens' Research Foundation.

Mr. Finney was a member of the American, Oklahoma, D.C. and Federal Bar associations, the American Judicature Society, Phi Delta Phi legal franternity, the National Lawyers Club and the Federal City Club.

He is survived by his wife, Sally Van Horn Finney, a daugthers, Susan Ford. of Oklahoma City, and the Rev. Kathleen Finney, of Roanoke.; Va.; his mother, Bettie Higgs Finney, of Idabel, and two grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the Washington Hospice Society or the Thomas D. Finney Memorial Fund at Washington Cathedral.