Osterman is a surname. Notable people with the surname include:

Russian

• Andrei Osterman (1686–1747), Russian statesman
• Ivan Osterman (1725-1811), Russian statesman

American

• Cat Osterman (b. 1983), American softball player
• Harry Osterman, Chicago politician
• Kathryn Osterman (1883-1956), American actress
• Lynne Osterman (b. 1962), American politician from Minnesota
• J.P. Osterman, American writer of science fiction

Slovene

• Ana Osterman (born 1940), Slovene politician

Swedish

• Oscar Osterman (1894–1956), Swedish Army officer

• Jon Osterman, a character in the Watchmen series, known more commonly as Doctor Manhattan

• The Osterman Weekend, a novel
• The Osterman Weekend (film)
• Ostermann
• Eastman (surname)