| Kexi Heinäharju | |
| Fullname: | Keijo Heinaharjo |
| Nickname: | Kexi |
| Birth Date: | 2 February 1955 |
| Hometown: | Jyvaskyla, Finland |
| Since: | 1975 |
| Darts: | 19g Tungsten |
| Laterality: | Right-handed |
| Bdo: | 1981–1993 |
| Bdo World: | Last 16: 1984 |
| Tournament: | Finnish Open |
| Resultyears: | 1981 |
Keijo "Kexi" Heinäharju (born 2 February 1955) is a Finnish former professional darts player.
Heinäharju won the 1981 Finland Open, beating fellow Finn Risto Nurmela in the final. He first qualified for the BDO World Darts Championship in 1984, defeating Danny Inglis in the first round before losing to Ceri Morgan in round two. He would make three further appearances in the World Championships in 1987, 1989 and 1991 but lost in the first round each time to Paul Lim, Steve Gittins and Eric Bristow.