Oster is a surname. Notable people with the surname include:
Adalbert Oster (born 1944), Romanian sports shooter Al Oster (1924–2017), Canadian singer Benedikt Oster (born 1988), German politician Bill Oster (1933–2020), American baseball pitcher Christian Oster (born 1949), French writer Dan Oster (born 1981), American actor and comedian Daniel Oster (1938–1999), French writer Eitan Oster (2001–2024), Israel Defense Forces officer Emily Oster (born 1980), American economist and academic, daughter of Sharon Ernst Oster (1908–1977), German pianist, musicologist and music theorist George Oster (1940–2018), American mathematical biologist Grigoriy Oster (born 1947), Russian author and screenwriter Hans Oster (1887–1945), German World War II general and resistance figure Harry Oster (1923–2001), American folklorist and musicologist Heinrich Oster (1878–1954), German chemist, businessman and war criminal Jack Oster (1902–1956), British rugby footballer Jeff Oster (born 1957), American New Age musician Jeffrey W. Oster, US Marine Corps lieutenant general Jennifer Oster (born 1986), German footballer Jerry Oster (1943–2020), American writer John Oster (born 1978), British football player and coach Josef Oster (born 1971), German politician Louis Oster (1928–2023), French lawyer Marcel Oster (born 1989), German luger Megan Oster (born 1989), American figure skater Pierre Oster (1933–2020), French poet Shai Oster, American journalist Sharon Oster (1948–2022), American economist and academic Stefan Oster (born 1965), German Catholic bishop
See also Sara Mathilde Øster (born 1973), Danish artist