Ostrom or Öström is a Swedish surname meaning "island stream". Notable people with the surname include:
Elinor Ostrom (1933-2012), American political economist
Ellen Ostrom, dancer in the New York City Ballet's corps de ballet
Gilbert Wellington Ostrom (born 1837), Ontario lawyer and political figure
Hans Ostrom (born 1954), American professor, writer, editor, and scholar
John Ostrom (1928–2005), American paleontologist
Magnus Öström, drummer for the Esbjörn Svensson Trio
Meredith Ostrom (born 1977), American actress, model, and painter
Tom Ostrom (1936–1994), American psychologist
Vincent Ostrom (1919-2012), American political scientist
Walter Ostrom, ceramic artist