Ulf Karl Erik Wakenius (born 16 April 1958) is a Swedish jazz guitarist, known as a member of Oscar Peterson's last quartet from 1997. He was also a member of the Ray Brown trio.
Wakenius was born in Halmstad and raised in Gothenburg. In the 1980s he played with Peter Almqvist in Guitars Unlimited, playing during the intermission for 600 million viewers of the Swedish International Finale of the Eurovision Song Contest in 1985. A stop in Rio de Janeiro resulted in three records with Sivuca: Aquarela Do Brazil (1985), Rendez-Vous in Rio (1986), and Let's Vamos (1987). He recorded Those Who Were (1996) and This Is All I Ask (1998) with Niels-Henning Ørsted Pedersen. Enchanted Moments (1996) was recorded with Lars Jansson, Lars Danielsson, and Raymond Karlsson. On Dig In (1997) he plays with Gösta Rundqvist, Yasuhito Mori, and Jukkis Uotila.