Did the Council of Trent create the Latin Mass?

No. The Council of Trent did not create the Latin Mass. Pope St. Pius V did not create it. The Roman Rite was already centuries old when they took it up. What they did was protect what existed.

By the 1500s, the Roman Rite — with its Canon dating to the fourth century, its calendar built up over a thousand years, its propers, its rubrics, its ceremonies — had been celebrated essentially intact for many generations across the Latin West. Local diocesan variations had multiplied. Some were innocent regional customs; others had introduced abuses. The Council of Trent (1545–1563) called for a careful pruning of these accretions and a return to the Roman use as it had been.

In 1570, Pope St. Pius V promulgated the resulting Missal with the bull Quo Primum. He did not invent its contents. He standardized them. He explicitly ordered that any rite of less than 200 years’ standing be conformed to the Roman Missal, while older venerable rites — the Ambrosian, the Mozarabic, the Dominican — were preserved. Quo Primum granted the Roman Missal in perpetuity to every priest of the Latin Rite, free from any obligation to use anything else.

The Tridentine Missal is therefore Tridentine in promulgation, but Roman in substance. Trent did not write the Mass. The Mass came to Trent already given, by tradition, by the saints, by the early Roman Church. Trent received it and handed it on.

Go deeper → The Mass of the Ages