RAF Kinloss in Moray will cease to exist as an operational air base after 31 July.
The runway will be closed and air traffic controllers, firefighters and some ground staff will be transferred to other facilities after that date.
It is a result of the cancellation of new Nimrod orders last year after a review.
The Ministry of Defence has suggested that Kinloss may still have a future as a military establishment.
This centres on thousands of British troops being withdrawn from bases in Germany, but no decisions have yet been made.
The future of neighbouring RAF Lossiemouth remains uncertain.
A decision on RAF Lossiemouth, and that of RAF Leuchars in Fife, will be announced after the Scottish elections on 5 May.
An MoD spokeswoman said: "The airfield at Kinloss will cease to function on 31 July. The rest of the base will stay open and the gradual drawdown of staff will take place over a few years, completing in 2014.
"There may still be an alternative military use for RAF Kinloss."
Moray MP and SNP defence spokesman Angus Robertson said: "The closure of RAF Kinloss will be a very sad day for the servicemen and women, the civilian staff and the local community.
"Speculation about the future use of the RAF Kinloss, combined with the uncertainty over the future of RAF Lossiemouth, is having a devastating effect on Moray."
A conference aimed at creating new jobs in Moray amid fears over the future of the RAF in the area was held on Wednesday.
It was organised by Moray Chamber of Commerce.