Underhill will earn his 25th international cap at Twickenham Stadium on Saturday (15.15 kick-off) while Ewels and Stuart will get their opportunities as replacements.
It will England’s opening game of the Autumn Nations Series before they face Australia and South Africa.
Head coach Eddie Jones said: “We’ve had two good preparation camps in Jersey and Pennyhill Park, worked really hard and we’re ready for a tough, physical game.
“We respect Tonga greatly and we know that with props like Siegfried Fisi’ihoi and Ben Tameifuna, we are going to have to go in the front door before the back door.
“We’re especially looking forward to getting back out in front of a full crowd at Twickenham and playing some entertaining, exciting rugby for all of the supporters, we can’t wait to have them back.”
Meanwhile Sunday could be a huge occasion for Josh Bayliss.
The homegrown back rower has been named as a replacement for Scotland who face Australia.
Bayliss has been in Scotland camps previously - including the 2021 Six Nations - but has yet to run out on the international stage.
He qualifies for Scotland via his Aberdeen-born grandmother, Frances Bayliss, and deserves his opportunity to shine on the biggest stage after an impressive few years in Blue, Black and White.
Scotland head coach Gregor Townsend said: “While there were several positives to take from the win against Tonga we face a very different opponent in Australia this week.
“They are coming into this fixture clearly off the back of good results and full of confidence, so we will need to bring focus, accuracy and aggression for the full 80 minutes.
“We have been able to select an experienced team with the availability of our players outside of Scotland and aim to use the remaining Autumn Nations Series fixtures to build our game through improving week on week.
“This is a great opportunity to test ourselves against an in-form side, who are also one of the leading teams in world rugby.”