45s or 45S may refer to:

Silver Lake Forest Service Strip (FAA identifier: 45S), an airport in Lake County, Oregon, U.S. Forty-fives, a trick-taking card game 45s: 45 rpm 7" vinyl single records spun at forty-five revolutions per minute (rpm or RPM); some Gramophone records also spun at 45 rpm. The Forty-Fives, a rock band formed in Atlanta, GA in 1998 FourFiveSeconds, a song by Rihanna, Kanye West and Paul McCartney Soldiers in the Jacobite army of the Jacobite rising of 1745 Sulfur-45 (45S), an isotope of sulfur

See also S45 (disambiguation)