The crowd estimated in the thousands argued the charter would help end religious oppression and ensure equality between men and women.
The protest was led by several high-profile Quebec women, including actress Janette Bertrand, who wrote an open letter in support of the charter.
Lise Rousseu, one of the protesters, says the charter will serve as a model not just for Quebec society, but for the world as a whole.
The Parti Quebecois government wants to ban public employees from wearing obvious religious symbols, including the Muslim headscarf, in the workplace.
The PQ has a minority and would require opposition support to make the charter law.
Protests for and against the charter have been held regularly since the plan was announced in early in September.
A protest opposing the plan is scheduled for Sunday in Montreal.