World Theatre Day was initiated in 1961 by the International Theatre Institute ITI. It is celebrated annually on the 27th March by ITI Centres and the international theatre community. Various national and international theatre events are organized to mark this occasion. One of the most important of these is the circulation of the World Theatre Day Message through which at the invitation of ITI, a figure of world stature shares his or her reflections on the theme of Theatre and a Culture of Peace. The first World Theatre Day Message was written by Jean Cocteau in 1962.

Ever since, each year on the 27th March (date of the opening of the 1962 "Theatre of Nations" season in Paris), World Theatre Day has been celebrated in many and varied ways by ITI Centres - of which there are now more than 90 throughout the world. Moreover theatres, theatre professionals, theatre lovers, theatre universities, academies and schools celebrate it as well.

Each year an outstanding figure in theatre or a person outstanding in heart and spirit from another field is invited to share his or her reflections on theatre and international harmony. What is known as the International Message is translated into more than 50 languages, read for tens of thousands of spectators before performances in theatres throughout the world, and printed in hundreds of daily newspapers. Colleagues in the audio-visual field lend a fraternal hand, with more than a hundred radio and television stations transmitting the Message to listeners in all corners of the five continents.