Robert Osborn Boyd, 76, a former member and chairman of the National Mediation Board who was working as an independent arbitrator in labor disputes, died Monday of pneumonia at Georgetown University Hospital. He had cancer.

Mr. Boyd was born in Kennewick, Wash. He first lived in Washington in the 1930s, when he worked for the late Sen. Frederick Steiwer (R-Ore.) and attended George Washington University's law school at night.

After three years, he learned he could take the Oregon bar examination without a law degree. He then returned to Portland, passed the bar exam and began practicing law.

In 1954, after being named to the National Mediation Board by President Eisenhower, he returned to this area. Two years later he earned his law degree at George Washington University.

Mr. Boyd served as chairman of the board from 1956 to 1960 and resigned the following year. He then began working as an independent arbitrator for both the National Mediation Board and the Federal Mediation and Conciliation Service.

He began his career in labor mediation in Oregon, where he was a mediator and referee on numerous boards under the Railway Labor Act. Before that, he was counsel to the Oregon Liquor Control Commission and campaign manager for former Oregon Gov. Charles A. Sprague.

Mr. Boyd graduated from Amherst College in Massachusetts and was awarded an honorary degree from the college in 1961.

He served in the Coast Guard during World War II.

He lived in Alexandria and was a member of the National Academy of Arbitrators and the University Club in Washington.

Survivors include his wife, the former Jacqueline Zurcher, of the home; a son, Marine Col. Daniel Z., of Norfolk; a sister, Katherine Long, of Los Angeles, and two grandchildren.