Here is the list of some of the Best Museums in Toronto:
1. Casa Loma

Why go: Canada might be a relatively young country, but that doesn’t mean Toronto can’t have its very own castle. The former home of Canadian financier Sir Henry Pellat fits the bill perfectly. Get your fill of Downton Abbey-esque rooms before heading to the Queen’s Own Rifles Museum on the third floor.
2. Royal Ontario Museum

Why go: Stop by the Royal Ontario Museum to learn about everything from the art of the First Peoples to modern fashion to the age of dinosaurs. The museum has an ever-evolving schedule of exhibitions and events, including the summer-long Friday Night Live, which transforms the galleries into a party with live DJs, food, and drinks.
3. Art Gallery of Ontario

Why go: Toronto-born architect Frank Gehry redesigned the gallery to be a sculpture in its own right and its collection contains more than 95,000 works of art, including a vast collection of Canadian art.
4. Bata Shoe Museum

Why go: The collection includes more than 13,000 items on display, with shoes from the ancient world to the present day, all housed in Raymond Moriyama’s award-winning structure.
5. Hockey Hall of Fame

Why go: Even visitors have to pay tribute to Canada’s hockey greats—it’s practically a law in this ice-obsessed nation. Visit the permanent home of the Stanley Cup, face off against famed players in the Shoot Out simulation and check out the unrivaled collection of jerseys and other relics in the massive Tissot World of Hockey Zone.
Source: timeout
If you have any more queries, you can ask your question in the forum of Canadians Live.