"Grease" is the title song for the musical motion picture Grease, which was based on the stage play of the same name. The song was sung by Frankie Valli and was featured twice on the film's soundtrack; as the first track, and reprised as the final track. It became a number one single in the United States during 1978 and it also became a Top 30 R&B hit in the same year. The song was written by Barry Gibb of the Bee Gees; that group would later perform the song in concert, as captured on their live offering One Night Only. After "Grease" hit #1 on the Billboard Hot 100, Barry broke the record for '#1 Songs Written in a Calendar Year.' He was responsible for writing or co-writing 7 #1 songs in 1978, breaking the record of 6 set by Lennon/McCartney in 1964. The other songs were "If I Can't Have You" (an Yvonne Elliman hit), "Stayin' Alive", "Night Fever", "How Deep is Your Love" (Bee Gees hits), "(Love Is) Thicker Than Water", and "Shadow Dancing" (Andy Gibb hits.)

"Grease" was covered by experimental rock band Dog Fashion Disco and included as a hidden track on their album Committed to a Bright Futureand sampled in the track "I Want You" by Paris Hilton on her first studio album as well as "Rock The Party", a 2001 single by UK boy band Five. Part of the song was also interpolated in "Joints & Jam", a 1998 single by Black Eyed Peas as well as being heard in the song Blue Angels by Pras released in the same year. The song was also covered by UK girl group Girls Aloud. The song was also sampled by De La Soul on their 1991 song "A Roller Skating Jam Named 'Saturdays'".