Wickremesinghe was also on the board earlier.
The government is to take over management of Sri Lankan Airlines from April 1 when the management contract with Emirates ends.
Two existing board members, Tim Clarke and Gary Chapman, will remain on the board to represent Emirates, which still retains a 43.6 percent stake in the airline.
The Emirates management came to an end after the Middle Eastern airline decided not to renew its 10-year management deal following months of inconclusive and often acrimonious talks with the Sri Lankan government.
The government has said it was seeking a greater say in the management of SriLankan airlines. Updated