Around 50 extra parking spaces will be created, taking the total number to 105.
The project will also see new dedicated blue badge parking bays, a drop-off point, new lighting and CCTV coverage.
This scheme is part of West Yorkshire Combined Authority’s £32.5m programme of railway car park extensions and follows on from the town’s new public transport hub, which was opened in November.
West Yorkshire Combined Authority transport chair, Coun Keith Wakefield said: “Extending South Elsmall car park supports sustainable economic and employment growth by improving people’s access to the main urban centres where new, good-quality jobs are being created.”
Construction at South Elmsall is expected to take at least 13 weeks. While the work is in progress approximately 30 parking spaces will be available each day.
Subject to affordable and deliverable designs, other stations that will benefit from car park extensions include Fitzwilliam, Mirfield and Normanton, while a future scheme is also being explored at Morley.