The withdrawal of a Ryanair route to London Stansted saw the number of domestic passengers using Edinburgh airport drop last month.
A 6.1% fall in domestic travellers to under 460,000 had a “big influence” on the overall decline of 1% year-on-year in October to 1.3 million.
Ryanair cut Stansted frequency from four flights a day to four a week in June before withdrawing the service altogether last month.
It was the first time in five years, apart from severe weather caused by the ‘Beast from the East’ in March 2018, that the Scottish capital’s airport has suffered a decline in numbers.
However, international passengers grew by 2% to more than 850,000 in October.
Airport chief executive Gordon Dewar said: “We’ve had almost 60 months of continuous growth and it’s unfortunate that we’ve seen this temporary fall in passenger numbers – something we earlier this year predicted would happen.
“It shows us that growth is not guaranteed and it is only possible with hard work and a collaborative approach.
“The arguments around ADT [Scottish Air Departure Tax] are well known and we cannot hide the fact that we now have yet another obstacle to work around to deliver that growth that has become expected.
“Connectivity is important to Scotland and our initial talks with the Scottish government about bringing the world closer to Scotland have been positive.
“As an airport, we play our part in tourism, business, education, research and culture, so ensuring a sustainable future for the industry is very important. We need to work together to deliver that.”