"They Shall Not Grow Old" premiered simultaneously at the BFI London Film Festival and in selected cinemas in the UK on 16 October 2018, before airing on BBC Two on 11 November 2018 (the hundredth anniversary of the Armistice of 11 November 1918); it received a limited US release on 17 December. Following its box office success, the film received a wide theatrical release in February 2019 (the film's theatrical release was handled by Warner Bros. Pictures). It was acclaimed by critics for its restoration work, immersive atmosphere and portrayal of war, and earned a nomination for the BAFTA Award for Best Documentary.