Brookside is a British television soap opera, set in Liverpool, England, which began on the launch night of Channel 4, 2 November 1982. It ran for 21 years until 4 November 2003. It was produced by Mersey Television and conceived by Grange Hill and Hollyoaks creator Phil Redmond.

Brookside was Channel 4's highest rated programme from the mid-1980s to the mid-1990s, with audiences regularly in excess of seven million. Initially notable for its realistic and socially challenging storylines, from the mid-1990s the show began raising more controversial subjects under new producers such as Mal Young and Paul Marquess. It is especially well known for broadcasting the first pre-watershed lesbian kiss on British television in 1994, as well as a domestic abuse storyline resulting in murder. It also had the first gay character on a British TV series, who was outed in a 1985 storyline. In 1996, the series experienced an extreme backlash from viewers when it featured a hugely controversial storyline focusing on an incestuous sexual relationship between two siblings, and from that point the show became notable for its more outrageous and improbable storylines.

Although the series had a long and successful run, its viewing figures were in terminal decline by 2000, and low ratings eventually led to its cancellation in June 2003. The final episode was broadcast on 4 November 2003 and was watched by around two million viewers.

The first episode of Brookside was repeated as part of Channel 4 at 25 on 1 October 2007. The episode aired on More4 in a season of celebratory Channel 4 programmes to mark the channel's 25th anniversary. Several classic episodes have also been available to view on All 4 since 2009. After years of campaigning by fans, the special DVD Brookside Most Memorable Moments was released in November 2012, just over 30 years after the series originally began. It features clips and episodes from the programme's 21-year history. In January 2023, STV Player signed a deal with distributor All3Media to become the first streaming service to provide every episode. Original cast members Claire Sweeney and Sunetra Sarker praised the decision to relaunch the show on STV Player.