On March 21, 1929, he married Märtha of Sweden, like him a direct descendant of Josephine de Beauharnais, with whom he had one son Harald, and two daughters, Ragnhild and Astrid. As exiles during World War II, Crown Princess Märtha and the royal children lived in Washington, D.C, where she struck up a close friendship with Franklin Delano Roosevelt. She died in 1954, before her husband ascended the throne.

Olav V was succeeded by his son, Harald V, upon his death.