Arthur J. Gartland '36, the only Boston School Committee incumbent supported by civil rights leaders, was defeated yesterday in his bid for re-election to a third term.

Mrs. Louise Day Hicks, chairman of the committee and a consistent opponent of busing to end racial imbalance in Boston schools, drew away from the other nine candidates for the five spots on the committee.

Thomas S. Eisenstadt. Joseph Lee Jr., and William E. O'Connor, three incumbents who have agreed with Mrs. Hicks on most racial issues, ran behind her in the early balloting but ahead of the five-man Citizens for Boston Schools slat-supported by civil rights leaders.

In the race for the fifth place, John J. McDonough, who had been supported by Mrs. Hicks, took a substantial early lead over Gartland. Gartland had run fifth and McDonough ninth in the September primary.

Roxbury social worker Melvin King, the only Negro in the race, was running well behind Gartland, and other Citizens for Boston Schools candidates brought up the rear.