The three-match ODI series is slated to begin on June 29.
Garton, 24, has impressed head coach Chris Silverwood with his performances in white-ball cricket for his county and makes the national side for the first time.
"We have been monitoring the progress of George Garton for quite some time. He has been a significant part of Sussex’s bowling unit in white-ball cricket for an extended period," Silverwood said in a media release.
"His ability to bowl quick with his point of difference being a left-armer certainly gives us options in this series, and he deserves his chance at this level.
Apart from the injured duo of Ben Stokes (broken finger) and Jofra Archer(elbow), England haven't rested any of their leading cricketer for the series, which has been a feature of their rotation policy amid the COVID-19 pandemic.
"This ODI series is important as we continue to build momentum ahead of the 2023 World Cup. Despite some injuries, the squad I have selected is strong and gives us depth across all departments. We are looking forward to competing and putting on a show for the fans," Silverwood said.
Saqib Mahmood and Reece Topley were unavailable for selection due to injuries while Olly Stone suffered a stress fracture in his back during the recent second Test against New Zealand at Edgbaston, which ruled him out for the rest of the English summer.
"Several players are not available for selection due to injury. Jofra Archer (right elbow), Saqib Mahmood (abdominal) and Reece Topley (side strain) are all missing, but continue to make excellent progress from their respective injuries," Silverwood stated.
"We are pleased that Ben Stokes is returning to action with Durham this weekend after recovering from a fractured finger. If everything goes to plan, I hope he could be available for selection for the Vitality IT20 series against Pakistan next month.
"Unfortunately, following the second Test at Edgbaston against New Zealand, Olly Stone has been diagnosed with a stress fracture of his lower back and will miss the rest of the summer with the injury. It is a great shame as Olly was showing real promise with the ball and would have been part of our selection plans for this series."
The three-match ODI series will get underway on June 29 at Riverside Ground, Chester-le-Street.
England ODI Squad:
Eoin Morgan (C), Moeen Ali, Jonathan Bairstow, Sam Billings, Jos Buttler, Sam Curran, Tom Curran, Liam Dawson, George Garton, Liam Livingstone, Adil Rashid, Joe Root, Jason Roy, David Willey, Chris Woakes, Mark Wood