Oh What a Lovely War is a theatrical chronicle of the First World War, told through the songs and documents of the period. Devised and first performed by Joan Littlewood's Theatre Workshop at the Theatre Royal, Stratford East, London in 1963, it received the acclaim of London audiences and critics. It won the Grand Prix of the Théâtre des Nations Festival in Paris that year and has gone on to become a classic of the modern theatre.

In 1969 a film version was made which extended the play's popular success. The play is now on the standard reading list of schools and universities around the UK and was revived by the Royal National Theatre in 1998, and by the Theatre Royal, Stratford East, in 2014. This new edition of the play, published to coincide with the 2014 revival of the play at its original home on the centenary of World War I, is as edited by Joan Littlewood and returns the script to its original version.

The edition includes an introduction by Joan Littlewood and an afterword by Victor Spinetti.