Stagecoach says that Boxing Day sales has led to an increase in people wanting to go shopping as people favour bargains over turkey sandwiches.
The company will run a special timetable so shoppers can catch buses after Christmas parties or hitting the sales.
A N700 service will run between Durrington, Broadwater, Tarring, Worthing, South Lancing, Shoreham, Hove and Brighton every 30 minutes.
The same service will also run on New Years Day.
Mark Turner, commercial director for Stagecoach, said: “Due to the increase in shopping opportunities and the popularity of Boxing Day sales, we believe there is demand for a service on this day.
“While some people may still be tucking into turkey sandwiches, other Worthing and Brighton residents are keen to be first in line at the sales and customers told us they’d like to be able to reach those bargains on the bus, rather than having to drive.”
“The period is a time where people travel to see friends and family and we hope these additional services will provide them with a public transport option to spread their own festive cheer.”