The new livery is one a series of ways of marking the anniversary with the launch of a hotel division also lined up.
Brits will get a first proper taste of the new livery when the first aircraft to be given it, an Airbus A330, touches down on November 17 at Gatwick.
The airline, which carries 500,000 Europeans a year, flies from Gatwick, Manchester and Glasgow to destinations across Canada, including Toronto, Montreal, Vancouver and Calgary, and offers a summer service from Dublin.
Transat president and chief executive Jean-Marc Eustache said: “I feel a great sense of pride when I look at how far we’ve come since November 14, 1987, when our first flight took off from Montreal bound for Acapulco.”
“And our journey is far from over. While our tour operating business and our aviation operations are tried and tested, our services continue to evolve to meet the expectations of travellers today and in the future.
“We have plenty of innovations coming up, including the new fleet livery that we are unveiling this evening, and the new hotel division that we are about to create, all in pursuit of our goal of remaining at the forefront of the travel industry.”