In Asia, you can find firm tofu at the stall selling tofu products in wet markets. Packages of firm tofu are also sold in almost all supermarkets. In the US and elsewhere, firm tofu can be found in packages in refrigerated shelves at most supermarkets and grocery stores, as well as in Asian and Chinese supermarkets. Wal-Mart, Target, Trader Joes, Whole Foods are just a few examples of stores where you can purchase firm tofu.