Walter John Stoessel Jr. (January 24, 1920 – December 9, 1986) was an American diplomat.

The paternal side of his family had migrated to the United States from western Germany in the middle of 19th century.

During his term as ambassador to Poland, Stoessel initiated contact with China and hosted talks on behalf of the United States, directly opening the door for President Richard Nixon's famous visit to China.

[1] In 1981, while ambassador to West Germany, he joined the delegation, with Walter Mondale, greeting the U.S. hostages released by Iran when they deplaned.

During his term he served briefly as acting Secretary of State between the tenures of Alexander M. Haig and George P. Shultz.