The no-frills carrier said it would be making a 14% reduction in the number of weekly flights for winter 2008/09 at the airport.
They will be cut from more than 1,850 to just under 1,600 this winter and the airline says it will carry around 900,000 fewer passengers than last winter.
Ryanair has 36 planes based at Stansted but this will be reduced to 28.
It follows the airline's announcement earlier this week of fewer flights this winter from Dublin.
Ryanair blamed the capacity cutback on a number of factors.
These include the huge hike in oil prices, the cost of using Stansted and what it says is the total failure of the Civil Aviation Authority regulatory regime to control costs for airlines at the airport.
The airline has also announced that it is suspending operations at seven airports for over a month this winter.
The airline said it was closing its operations from Basel, Budapest, Krakow, Palma, Rzeszow, Salzburg and Valencia from Tuesday 4 November until Friday 19 December.
