Cowan is a small outer suburb of Sydney, in the state of New South Wales, Australia, approximately 40 kilometres (25 mi) north of the Sydney central business district, in the local government area of Hornsby Shire. Cowan shares the postcode of 2081 with Berowra. Brooklyn, which lies 6 kilometres (3.7 mi) to the north-east of Cowan, is considered the northernmost suburb of the Greater Sydney Metropolitan Area.

In the 2021 census, there were 631 people in Cowan. 81.9% of people were born in Australia, the next most common countries of birth included England 3.5%, Korea, Republic of (South) 1.6%, South Africa 1.6%, New Zealand 1.4% and the Philippines 1.3%. 91.3% of people spoke only English at home, the next most common languages spoken at home included Korean 1.1%, Persian (excluding Dari) 1.0%, German 0.6%, Dutch 0.6% and Finnish 0.6%. The most common responses for religion were No Religion 46.0%, Anglican 15.8%, Catholic 13.5%, Christian, not further defined 6.0% and Uniting Church 3.0%.

Access by road to Cowan is via the Pacific Highway which traverses Cowan north to south. The M1 Sydney to Newcastle Freeway runs past Cowan.