Sign O' the Times is the ninth studio album by Prince. It was first released on March 31, 1987, as a double album. The album is the follow-up to Parade and is Prince's first solo album following his disbanding of the Revolution. The album's songs were largely recorded during 1986 to 1987 in sessions for releases Prince ultimately aborted: Dream Factory, the pseudonymous Camille, and finally the triple album Crystal Ball. Prince eventually compromised with label executives and shortened the length of the release to a double album.

Sign o' the Times' release was supported by several singles, among them the socially conscious "Sign o' the Times" and "If I Was Your Girlfriend", in addition to a well-received concert film of the same name. The album peaked at number six on the Billboard 200 and was certified platinum by the RIAA four months after its release. It also reached the top 10 in Austria, France, New Zealand, Norway, Sweden, and the UK and number one in Switzerland. "Sign o' the Times", "U Got the Look" and "I Could Never Take the Place of Your Man" were all top 10 hits on the Billboard Hot 100. 

Writing for The Rolling Stone Album Guide (2004), Michaelangelo Matos regarded it as "the most complete example of Prince's artistry's breadth, and arguably the finest album of the 1980s". In 2017, the album was inducted into the Grammy Hall of Fame.