Langley began his career as an apprentice with Chelsea, making his debut in 1975 against Leicester City, when aged 16[3] years and 9 months.
He first established himself in the side during Chelsea's first season back in the First Division in 1977–78, during which he scored 13 goals, making him the club's top scorer.
After Chelsea's failure to gain instant promotion in 1979–80, Langley joined Queens Park Rangers for £400,000 in August 1980.
Langley only appeared in five matches for the Greek club and returned to England to play for Coventry City halfway into the season.
After his stint with the Wanderers and Aldershot, Langley left Europe in 1985 to play for Hong Kong-based South China.
Langley then went on to finish his English career with Exeter City where he appeared in 21 matches scoring two goals during the 1988–89 season with the club.
Langley joined Chelsea TV when it launched, as a regular guest on the Live From Stamford Bridge phone-in show.