A number of comedy stars have filmed contributions from their homes.
Miranda Hart and the cast of Miranda in self-isolation
The Vicar Of Dibley's Lockdown Sermon
Catherine Tate and David Tennant: Lauren the 'Am I Bovvered' teenager gets home-schooled
Matt Lucas and his Baked Potato song with music from the BBC Orchestra
Jack Whitehall in Bad Education, with Mathew Horne and heavyweight champion Anthony Joshua
Peter Kay and the British public remake the song Amarillo
Romesh Ranganathan with an Isolation Diary
Elsewhere in the show Gary Barlow is joined by friends including Liam Payne, Olly Murs, Leona Lewis, Nicole Scherzinger, Freya Ridings, Katherine Jenkins, Alfie Boe, Gregory Porter and more performing Sing; Dave Grohl and friends premier a new BBC Radio 1 Live Lounge version of Times Like These; Sam Smith sings Lay Me Down and Celeste covers Lean On Me.
Also: There'll be an EastEnders Queen Vic virtual pub quiz hosted by Ian Beale; a Strictly Come Dancing choreography routine; a Doctor Who contribution; and "exercise secrets" from Joe Wicks.
The producers say: "The Big Night In will celebrate the acts of kindness, humour and the spirit of hope and resilience that is keeping the nation going during the unprecedented COVID-19 pandemic with a special night of programming."