Big Brother (British TV series) series 21

Production

The series was confirmed in August 2023 at the Edinburgh International Television Festival, when ITV commissioning editor Paul Mortimer announced the show would return for a twenty-first series in 2024 as part of two six-week runs. Applications opened on 17 November 2023, during the final of the previous series, and closed on 31 July 2024. The format remained the same as the prior series, with 36 episodes airing six nights a week from Sunday to Friday.

The launch show was live, contributing to the 41-day run, the shortest in the show's history. ITV stated the series would feature a new cast of carefully selected housemates, with shopping tasks, nominations, live evictions, and public voting returning. Hosts AJ Odudu and Will Best teased that tasks would be taken up a notch. In April 2024, reports that the Big Brother house would move from Garden Studios due to disruption from a nearby canal were debunked a month later; planning applications confirmed the house would remain at Garden Studios, with the live set and garden in the same location as the previous series.

On 4 October 2024, Richard Arnold toured the kitchen and living area on Good Morning Britain, and ITV released photos of the house later that day. The house kept a similar structure but featured updated colour schemes and decor resembling dripping paint, adapting the eye logo theme; the diary room chair had multi-coloured cushioning and a dripping-paint frame.

Nominations table

The series introduced the Head of House role, which granted immunity from nominations and the choice of a Killer Nomination (single-handedly nominating a housemate for eviction) or a Save & Replace (saving a nominee and nominating a replacement). On Day 1, housemates chose between a red or blue side; the blue side became housemates, while the red side were designated non-housemates and sent to storage. Both sides then competed in battles to switch places, with those left in storage facing the public vote.

On Day 2, Martha won a battle against Ryan, gaining housemate status and choosing Hanah and Rosie to join her; Ryan went to storage. Segun won against Daze and remained a housemate. Thomas won against Rosie, gaining housemate status and choosing Marcello and Sarah; Rosie returned to storage. Daze won an endurance battle, securing housemate status and choosing Emma and Lily, leaving Baked Potato, Dean, Nathan, and Ryan to face the first public vote.

In another week, there were two Heads of House, Ali and Dean, and housemates nominated in pairs chosen by them: Hanah and Lily, Marcello and Khaled, Izaaz and Nathan, Martha and Segun, Sarah and Baked Potato, and Emma and Thomas. For one shopping task, housemates were split into Vampires and Villagers; the winning team got a luxury budget and nomination power, the losers got basic rations and could not nominate. On Day 28, as punishment for discussing nominations, Nathan was barred from becoming Head of House and from nominating that week.

Controversy and criticism

On Day 17, during the episode broadcast on 22 October 2024, housemate Ali Bromley wore a black t-shirt featuring a watermelon in the shape of the region of Palestine, a symbol of solidarity with Palestine amid the Israeli–Palestinian conflict. After the Campaign Against Antisemitism complained to Ofcom, ITVX took down both the highlight programme and the accompanying Late & Live episode. When re-uploaded, Bromley's t-shirt was censored, with the watermelon removed.