Redwatch was a British website associated with members of the far-right British People's Party. It published photographs of, and personal information about, alleged far left and anti-fascist activists. It typically targeted activists in political parties, advocacy groups, trade unions and the media. The website's slogan was "Remember places, traitors' faces, they'll all pay for their crimes", a quote from neo-Nazi musician Ian Stuart Donaldson.

The information gathered by Redwatch was indexed by cities or regions. Many of the people listed were members of the Unite Against Fascism or other anti-racist or left-wing groups, such as the Socialist Party (England and Wales), the Socialist Party (Ireland), Sinn Féin, Social Democratic and Labour Party, Alliance for Workers' Liberty, Workers' Power (UK) and Socialist Workers Party (Britain). Some Labour Party, Liberal Democrat and Conservative members were also listed. Trade unionists, in particular teachers and journalists, figured prominently in the listings. There were dozens of photographs of anarchists and single-issue protesters.^{[citation needed]}

A now-defunct printed magazine Redwatch was first published by the neo-Nazi paramilitary group Combat 18 in March 1992, when its slogan was "oderint dum metuant": "let them hate as long as they fear" (a quotation from Caligula).

The website was hosted by Simon Sheppard, a former British National Party (BNP) member who was expelled from the organisation after circulating a leaflet which the leadership of the BNP regarded as a prima facie breach of race-discrimination legislation. Other BNP contributors to Redwatch included Adrian Marsden (a former BNP councillor in Halifax), Mike Lester (then the party's organiser in Stockport, named "Activist of the Year" at a Red, White and Blue festival organised by the party), Trevor Agnew (County Durham organiser and confidant of Nick Griffin, then the BNP leader) Mark Collett (then the Yorkshire BNP organiser), Keith McFarlane (a leading Sunderland activist at the time) and others. On 1 May 2005, Sheppard's home in Hull was searched by police investigating "incitement to racial hatred."

In January 2004, questions concerning the legality of the Redwatch website were raised in the House of Lords. The Home Office stated that listing public information online is not a crime.

The website has been heavily criticised by the Trades Union Congress and many affiliated unions. Following the TUC's annual Congress in September 2004, where an anti-Redwatch resolution was passed, the TUC General Secretary Brendan Barber wrote to Home Secretary David Blunkett, requesting a meeting to discuss the issue. Further discussions and correspondence with government members ensued, and in March 2005, a meeting took place with Home Secretary Charles Clarke. The TUC have promised to provide the Home Secretary with examples of experiences that trade unionists and other left-wing campaigners have had as a result of having their details published on Redwatch, whilst the Home Secretary promised to hold discussions with the police about what could be done to stop the activities of the website.

The website temporarily became unavailable around 6 December 2008, with all of its various URLs leading directly to error or Internet service provider pages. It returned later that month. On 2 March 2013 the anti-fascist Hope not Hate claimed that the police had arrested Kevin Watmough from Redwatch and confiscated his computers for investigation.

Redwatch justified its content as a reaction to leftist websites and magazines who display similar content: "Photographs and information about the reds who attempt to harass and assault British Nationalists and their families. The red scum target us, Redwatch plays them at their own game". Justifications provided by the website include an email circulated in August 2001 by the Anti-Nazi League, containing the home addresses of Nick Griffin (leader of the British National Party) and his mother, who was involved in the organisation of a BNP festival.