Police have charged a man who allegedly grabbed a woman from behind, dragged her to the ground, and sexually assaulted her as she walked along a beach footpath.

The incident occurred on Christmas Eve, 2018 at 5am around 300 north of Mullaloo Beach.

Police will allege a 28-year-old man was naked in a car park when a woman in her 40s walked passed on the shared pathway adjacent to the beach.

He has since been charged with sexual penetration without consent and is due to appear in Joondalup Magistrates Court on Thursday.

Detectives thanked the community for their assistance.