Yugoslavia's leading civil rights lawyer, Jovan Barovic, 56, was killed today in a car accident near Belgrade. A former wartime partisan and senior Communist Party official, he was widely known for his courageous defense of many political dissidents here over the past decade.

His clients included the writer Mihajlo Mihajlov, Croatian nationalists, pro-Soviet sympathizers, and Albanian minority rights activists. In addition, he was one of the closest friends and supporters of Milovan Djilas -- the former Yugoslav vice president who fell into disgrace after advocating a more liberal system of government.

Djilas said tonight that he had devoted himself to attempting to persuade Yugoslav officials to respect the country's own laws.

Invariably Mr. Barovic lost most of the political cases he defended. No Communist court has ever acquitted a political defendant and indeed, sometimes Mr. Barovic's clients were pronounced guilty in advance by top Yugoslav leaders. But he conducted each defense with an almost quixotic belief in law.

His last case, which ended last week, involved an appeal against the conviction of five Croat nationalists accused of planting a time bomb that exploded during President Tito's visit to Zagreb in 1975.

In court, Mr. Barovic claimed that his clients had originally confessed to planting the bomb only after severe torture by police. Pronouncing sentence, the court conceded that torture may have been used during the investigation, but nevertheless confirmed the maximum jail sentences of 15 years on charges of terrorism against three Croats.

Although frequently criticized in the Yugoslav press, Mr. Barovic was able to retain his independence partly because of his wartime record and partly because of his widely acknowledged integrity.

A Serb from Montenegro, he was expelled from secondary school for joining the Communist Party and was one of the first people to join in Marshal Tito's Communist uprising against the German occupation of Yugoslavia in 1941.

Wounded during the war, Mr. Barovic rose to become a colonel and a political commissar in the victorious partisan army. After the war, he seemed set for a brilliant political career in the new Communist state, but sided with Djilas in his dispute with Tito in 1954. Soon afterward, Mr. Barovic was expelled from the Communist Party and ostracized by his former friends and colleagues.

Without any other means of livelihood, Mr. Barovic studied law and was allowed to practice it from 1967, following a period of liberalization. He frequently took cases for which he was never paid and constantly traveled around the country.

Mr. Barovic is survived by his wife, a son, Nikola, a lawyer, both of Belgrade, and a daughter, Slavica, who lives in Paris.