Jari Mäenpää (born 23 December 1977) is a Finnish heavy metal multi-instrumentalist and songwriter. He is the founder of Wintersun for which he records all instruments except the drums. Before forming Wintersun, Mäenpää was best known for his role in the folk metal band Ensiferum, which he joined in 1996 after leaving his prior band named Immemorial. Wintersun was initially planned as a parallel project alongside Ensiferum, but in January, 2004 he was forced to leave Ensiferum due to clashes between their touring schedule and the studio recording time he had booked for Wintersun.