The meeting, which took place at Wembley in London, ended 1-0 in favor of the nominees.
The victory for Leicester was brought by the goal of Yuri Tielemans, who distinguished himself in the 63rd minute with a shot from outside the penalty area.
In the 90th minute, Chelsea managed to level the score, but the goal was canceled after watching the VAR.
For Leicester City, this FA Cup victory was the first in the history of the club, which was founded in 1884.
Leicester have made four finals in the past.
Chelsea have lost for the eighth time in the FA Cup Final, with eight wins.
Earlier it was reported that Manchester City set the England record for the most away matches without a defeat.