The pub chain, which operates from six UK airport locations, has written to its 1,000 airport pub employees and told them that a possible 400 to 450 positions are at risk of redundancy.
Staff at Gatwick, Heathrow, Stansted, Birmingham, Edinburgh and Glasgow airports will be affected.
"The decision is mainly a result of a downturn in trade in these pubs, linked with the large reduction in passenger numbers using the airports," says JD Wetherspoon chief executive John Hutson.
"We should emphasise that no firm decisions have been made at this stage.
"Wetherspoon is proposing to collectively consult with employees through an employment representative committee, which will be established for this purpose."
It comes a month after reports that more than 100 head office roles at JD Wetherspoon are at risk of redundancy.
In a letter to its 417 head office employees, the pub giant said that 110 to 130 people risk losing their jobs as it looks to scale back its operation.
According to Hutson, all head office staff, including those who are regionally based, will be affected.