Yan Yean is a locality in Melbourne, Victoria, Australia, 38 km north-east of Melbourne's central business district. Its local government areas are the City of Whittlesea and the Shire of Nillumbik. At the 2016 census, Yan Yean had a population of 252.
Yan Yean contains Yan Yean Reservoir. Melbourne's first reservoir, a 560 hectare lake with a capacity of 30,000 megalitres, was first established in December 1853 and provides water to Melbourne's northern and central suburbs. A park around the reservoir, managed by Parks Victoria, offers picnic, barbecue and walking facilities.