Firefighters had to use hoses and beaters to put out a sand dune and scrubland blaze.
About 2,500sqm of the east head of West Wittering beach went up at 3.30pm on Tuesday.
West Sussex Fire and Rescue Service sent a fire engine from Chichester and three Land Rover-style fire vehicles from other stations to get across the beach and tackle the threat.
One of the Land Rovers returned a few hours later to dampen down four hot areas.
The fire service ruled out arson, saying the cause was accidental.