There are several denim jacket manufacturers in Canada. Here are a few options you could explore:

Gildan Activewear: This company is based in Montreal, Quebec, and produces a wide range of clothing, including denim jackets.

Mark's: A clothing retailer with locations across Canada, Mark's offers a selection of denim jackets for men and women.

Naked & Famous Denim: A Montreal-based company that specializes in denim clothing, including jackets.

Jean Machine: This retailer sells a variety of denim jackets from different brands, including Levi's and Silver Jeans Co.

Silver Jeans Co.: This Manitoba-based company produces a variety of denim clothing, including jackets for men and women.

Oasis Jackets: Although based in the United States, Oasis Jackets has a strong presence in Canada and produces a wide range of denim jackets. Customization and private labeling is available here as per the customer's desire for many years. You can visit them at: https://www.oasisjackets.com/denim-jackets/

These are just a few of the options available in Canada. You may also want to consider searching online for other manufacturers or retailers that offer denim jackets.