Harry Kaj Olof Backlund (February 24, 1945 – December 25, 2013) was a Finnish jazz trumpeter, composer, arranger, bandleader, theorist, and one of the founders of the Helsinki Pop & Jazz Conservatory and the Jazz Department of Sibelius Academy. He was also one of the founding members of UMO Jazz Orchestra. He was a contemporary music education pioneer in Finland and a long-running senior music theory teacher in Helsinki Metropolia University of Applied Sciences. Kaj Backlund's sons Jari, Jukka, and Tapio are all musicians.