Teemu Keisteri (b. 22 September 1985) is a Finnish visual artist and DJ. He rose to fame by creating paintings and prints of the fictional character Ukkeli, which he created in 2008. Under the DJ persona Windows95man, he won Uuden Musiikin Kilpailu (Contest for New Music) alongside Henri Piispanen with the song "No Rules!" which went on to represent Finland in the Eurovision Song Contest 2024.