Honkajoki is a municipality in Satakunta, Finland. As of January 2014, more than 1,800 people lived there. Neighbouring municipalities are Isojoki, Kankaanpää, Karvia, Kauhajoki and Siikainen. The most notable water system is Karvianjoki. There are no lakes in the municipality. There are many untouched swamps.
Honkajoki was established in 1867.