The FCDO ended its travel advice to the destination after a state of emergency came to an end in the country on Saturday (27 August).
Tui said it was "proactively" contacting all impacted customers in departure date order to discuss their options.
"Please note this advice does not apply to customers transiting through Sri Lanka’s international airport," a Tui spokesperson added.
"We will continue to monitor the situation and update customers should there be any further updates. We would like to thank our customers for their understanding at this time."
