| Birth Date: | 3 November 1963 |
| Birth Place: | Český Těšín, Czechoslovakia |
| Death Place: | Košice, Czechoslovakia |
| Height Ft: | 6 |
| Height In: | 3 |
| Weight Lb: | 196 |
| Position: | Defence |
| Played For: | TJ Gottwaldov HC Dukla Jihlava HC Zlín |
| Ntl Team: | TCH |
| Draft: | 115th overall |
| Draft Year: | 1987 |
| Draft Team: | New York Rangers |
| Career Start: | 1982 |
| Career End: | 1990 |
Luděk Čajka (3 November 1963 – 14 February 1990) was a Czechoslovak professional ice hockey defenceman.
Čajka was drafted 115th overall by the New York Rangers in the 1987 NHL Entry Draft but never played in North America. He played in the Czechoslovak League for TJ Gottwaldov, HC Dukla Jihlava and HC Zlín (formerly Gottwaldov). He also represented Czechoslovakia in the 1987 World Ice Hockey Championships, winning a bronze medal.
On 6 January 1990, Čajka suffered severe spinal injuries after colliding with Anton Bartanus of VSŽ Košice and crashing into the boards in an icing situation during Zlín's game against VSŽ Košice. The injury left Čajka paralyzed and in a coma where he died on 14 February 1990. Zlín's stadium was renamed Zimní stadion Luďka Čajky in his honour.
His death led to the development of automatic, or "no-touch" icing where the violation is called automatically once the puck crosses the goal line.