"Time After Time" is a single by singer Cyndi Lauper, the second from her album She's So Unusual. It reached number one on the U.S. Billboard Hot 100 chart on June 9, 1984, and remained there for two weeks. Worldwide, the song is her most commercially successful single after "Girls Just Want to Have Fun", and reached number 3 on the UK Singles Chart and number 6 on the ARIA Singles Chart.

"Time After Time" was nominated for Song of the Year at the 1985 Grammy Awards. The ballad is considered a classic of the 1980s and is still played frequently on adult contemporary radio. The song is known for its numerous covers by a wide range of artists, including an instrumental version by Miles Davis.

Lauper co-wrote "Time After Time" with Philadelphia rocker Rob Hyman of The Hooters, who also supplied backup vocals to the song. In a 2006 interview with Sound Off with Matt Pinfield(episode 212) on HDNet, Lauper related how the song was written. She indicated much of the lyrics were written about occurrences in the studio and her life at the time. The line "the second hand unwinds" referred to producer Rick Chertoff's watch which was winding backwards.

Hyman explained in an interview with Songfacts that he and Lauper stayed in the studio after the sessions composing the song.

Drums were provided by a Linn drum machine, particularly the 'salt-shaker' sound. The guitar was recorded with a Marshall 2x12 combo amp, where a rackmountable Publison DHM89 harmoniser was used in the effects loop, set to delay-pitch-shift up the signal on the left channel and delay-pitch-shift up the signal on the right channel, to create a rich & lush chorus-like effect.

The video for "Time After Time" was about a runaway leaving her lover behind. The video opens with Lauper watching the 1936 film The Garden of Allah. Lauper sings (signs) the title of the song to the deaf as she is leaving the train station. The video was played in heavy rotation on MTV. Lauper's mother, brother, and then-boyfriend David Wolff appear in the video, and Lou Albano, who played her father in the "Girls Just Want to Have Fun" video, can be seen as a cook. The video was directed by Ed Griles. Portions of the video were filmed at the now closed Tom's Diner in Roxbury, the intersection of Central Ave & Main St in Wharton, New Jersey, and at the Morristown train station.

"Time After Time" has been covered, either in live performance or on a recording, by at least 120 different artists across a broad spectrum of genres. A partial list includes:

The song was used as a main theme sung by Katie Cook in View from the Top(2003). Mark Williams and Tara Morice performed the song in the Strictly Ballroomsoundtrack (in the scene where Scott and Fran dance on the rooftop). Eva Cassidy's version was featured in the TV series, Smallville, and it was added to the first Smallvillesoundtrack, The Talon Mix. The 2006 cover by Quietdrive appeared during the dance scene of the film John Tucker Must Die. It also contributed to a running gag in the second season of the TV series My Name Is Earl.

The song has been performed on American Idolthree times. In 2005, Nadia Turner performed the song on Billboard #1 Hits week in the fourth season. In 2007, Brandon Rogers performed the song on the second week of the semi-finals in honor of his grandmother in the sixth season. In 2009, 4th place finisher Allison Iraheta performed it as a duet with Lauper in the eighth season finale. Season 7 Semi-Finalists Kady Malloy and Colton Berry released a video of their cover on YouTube.

On Channel 4's show Mobileact Unsigned, The Bad Robots performed a version of this track.

INOJ's cover version of "Time After Time" reached number six on the BillboardHot 100 chart in 1998.

The song is briefly sung by Anna Kendrick's character as a karaoke song in the film Up in the Air.

Quietdrive's version can be heard in the film, John Tucker Must Die, during the food fight at John's birthday party. The song was also used in the 2008 remake of the film Prom Night. It peaked at number two on 's Bubbling Under Hot 100 Singles chart (the virtual equivalent of #102 on the Hot 100).

The song is featured numerous times in the film Romy and Michele's High School Reunion.

Elements of this song, mainly the guitar melody during the bridge, were used in the 2009 Black Eyed Peas song "Meet Me Halfway".