William's last shift as an operational captain at RAF Valley on Anglesey was on Tuesday, the BBC reported.
The 31-year-old Duke of Cambridge today took part in engagements alongside brother Prince Harry commemorating the anniversary of the 9/11 attacks.
William has been a search and rescue pilot for the last three years after deciding to take a secondment from the Blues & Royals, a cavalry regiment of the British Army, part of the Household Cavalry.
Since he was not allowed to go on active service due to his position as second in line to the throne - the plan of taking a secondment to the RAF was a way of allowing the Duke to lead a relatively normal working life.
The Duke will be moving back to Kensington Palace where he and his wife Kate and son's new apartments are also ready for them to move in to, media reports said.