The Interchange in Clifford Street shut at 10am yesterday (Sunday, March 15) and remains closed this morning.
Lancashire County Council, who own and operate the station, said the Interchange's supervisor had fallen ill with suspected coronavirus symptoms over the weekend.
After seeking NHS guidance, a decision was made to immediately close the building to safeguard the public.
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A spokesman for Lancashire County Council said: "Passengers and bus companies are still able to use Chorley Interchange, however we had to close the internal concourse on Sunday morning due to a staffing shortage related to advice issued via the NHS 111 service regarding suspected Coronavirus symptoms.
"We have staff on site for security and to direct passengers, and are working to reopen the internal concourse as soon as we can."
Cleaning staff have been on-site today to carry out a deep clean of the station.
The Council has not said whether the supervisor's symptoms have been confirmed as coronavirus.
Yesterday, Stagecoach tweeted: "Due to no council bus station supervisor, the bus station at Chorley is closed.
"All our buses are running as normal and dropping off at Chorley, but passengers when entering/alighting the bus must use the side gates."
Services are still calling at the station, but passengers must use the side gates and are unable to access the internal concourse.