Robert A. Olson, who has served as the acting commissioner of the Interior Department's Bureau of Reclamation since December 1983, has resigned, effective July 31, to become vice president of Resources Management International Inc. Olson had spent 22 years with the federal government, much of it with the Western Area Power Administration. A department spokesman said no decision has been made on a replacement.

President Reagan has announced that he will nominate John Douglas Scanlan, a veteran of diplomatic service in Eastern Europe, as ambassador to Yugoslavia, succeeding David Anderson. Scanlan, 57, entered the Foreign Service in 1956 and has served in Moscow, Warsaw and Belgrade, and in Montivideo, Uruguay.

At the Labor Department, Michael J. Walsh, a Portland, Ore., trial lawyer, has been appointed chairman of the Employees Compensation Appeals Board. The board resolves cases of federal employes appealing decisions by the Office of Workers' Compensation Programs on claims for job-related injuries and diseases. Walsh was legal counsel and assistant to the director of administration for the Reagan-Bush '84 campaign.

Robert R. Gleason Jr. has been named director of communciations and publications for the Advisory Commission on Intergovernmental Relations. Since April 1983 Gleason has served as special assistant to the president for intergovernmental affairs, with responsibility for liaison with state legislators and Indian tribal governments.

At the Treasury Department, Chester C. Bryant has been appointed comptroller of the Bureau of Alcohol, Tobacco and Firearms. Bryant joined the agency in 1965 as a special agent.

Michael J. (Joe) Cannon, a 22-year veteran of the Government Printing Office, has been appointed comptroller of the agency and head of its Financial Management Service.