The Halcyon is a British television period drama broadcast on ITV which began airing on 2 January 2017. It was created and written by Charlotte Jones. The series focused on examining World War II London from 'a new perspective', and was set in 1940 at a five-star hotel "at the centre of London Society and a world at war", aiming to show London life "through the prism of war and the impact it has on families, politics, relationships and work across every social strata." Steven Mackintosh and Olivia Williams play major roles. The first episode was broadcast on 2 January 2017, and the series concluded on 20 February 2017.

The series was cancelled after one series.