Former US Open champion Fitzpatrick and MacIntyre join already qualified Tyrrell Hatton, Viktor Hovland, Rory McIlroy and Jon Rahm in the team for the September 29-October 1 duel against the United States in Rome.
The six remaining spots in the European team will be revealed on Monday when Luke Donald names his captain's picks.
Fitzpatrick qualified alongside Hatton and Hovland on the World Points List following his tied third finish in the European Masters.
He will be playing in the Ryder Cup for the third time.
Scotsman MacIntyre will be making his debut in the biennial contest, qualifying via the European Points List alongside McIlroy and Rahm.
"There are many major milestones in every Ryder Cup journey but there is no question that finalising the automatic qualifiers for Team Europe is most definitely one of them," said captain Donald on Sunday.
"These six players have been standout performers throughout the qualification period and I am delighted to welcome each and every one of them officially to the 2023 team."
Meanwhile, Ludvig Aberg of Sweden claimed a maiden tour title victory at the European Masters.
The former world amateur number one carded a closing 64 at Crans-sur-Sierre to deny Fitzpatrick a hat-trick of titles in the Swiss mountains.
Aberg birdied his four of his last five holes to finish on 19 under for the week, two ahead of Sweden's Alexander Bjork.
Long-time leader Fitzpatrick finished in a tie for third with Scotland's Connor Syme after a bogey at the 18th.
"I've always had that belief that I've been able to do it, but to do it is pretty cool," said Aberg.
