OSU can stand for:

  • Institutions of higher education:
    • Ohio State University
    • Oregon State University
    • Oklahoma State University
    • Oswego State University (formerly State University of New York (SUNY) at Oswego)
  • The Order of St. Ursula or Ursulines (Roman Catholic Christian religious order)
  • Osu, Accra, a district in Ghana
  • Igbo culture:
    • Osu caste system, a caste system practiced by the Igbo people in West Africa
  • Operation Straight Up, an evangelical organization that provides faith-based entertainment to the United States military
  • Japanese culture:
  • Ōsu, district of Nagoya
    • Osu!! Karate Bu (manga)
    • Osu! Tatakae! Ouendan (Nintendo rhythm game)
    • osu! (a freeware clone of Osu! Tatakae! Ouendan)
    • Japanese for "Patience with myself and others" used in karate
      • Also used in JIKC, Kyokushin where it means "to push and to endure," a shortening of the words "oshi shinobu," and Wado-ryu Karate.