A watch cap is a tight-fitting knit cap worn in cold weather, typically issued to navy personnel. The watch cap is usually brimless, but some models include a small front brim. Government issued watch caps are 100% wool, but other textiles may be used for commercial products. A watch cap is also a fairly simple knitting project, and you can find instructions on making your own at a fabric or craft store or online.

The watch cap is often made so that the bottom part is folded up, though it can be pulled down low over the ears. Alternatively, the watch cap may simply cover the head without being folded over; this is typically the case with watch caps featuring a brim or visor. Some watch cap models are made to fit the top of the head snugly, while others leave a bit of material loose on the top of the head.

Wool watch caps are considered the best quality, as well as the warmest, but they are often too hot to be worn indoors as a fashion statement. A watch cap is a good project for a beginning or experienced knitter, and you can use any color and fiber of yarn you like. If you are not up to making your own, there are many vendors who offer watch caps in custom colors or with personalized embroidery.

The look of the watch cap is most often associated with sailors, but the headgear is also popular among clubgoers and anyone who lives in cold areas. It is the unofficial national headgear of Canada, where it is called a tuque or toque. The watch cap has many other alternative names as well, including beanie, boggan, knit cap, knit hat, ski cap, ski capor, skull cap, skully, sock cap, stocking cap, and toboggan. In India, the watch cap is known as a monkey cap.