SmartWool is an American company founded by New England ski instructors Peter and Patty Duke in Steamboat Springs, Colorado in 1994 and acquired by the Timberland Company in 2005. The company makes eponymous products primarily from treated merinowool. SmartWool claims that this proprietary treatment makes its products itch-free and resistant to shrinking. SmartWool is additionally claimed to have moisture-wicking performance and odor-reducing, anti-microbial properties; it is thus marketed primarily as performance apparel. Reviews for SmartWool products are typically found in the context of equipment for hiking and additional outdoor activities. They offer products for women, men, and kids.

In 2005, SmartWool implemented the requirement that its New Zealand wool suppliers no longer practise mulesing. In 2010, SmartWool signed a contract to exclusively source its Merino wool from the New Zealand Merino Company.