The Wizards acquired Sam Dekker from Cleveland via Milwaukee and swapped second-round draft picks with Cleveland, with the Cavs sending the Wizards' 2021 pick back to Washington for the Wizards' 2022 selection.
"First and foremost, I'd like to thank George Hill," Cavs general manager Koby Altman said. "He helped us get to the NBA Finals last year and has been a consummate professional on the court and in our community. Both George and Sam Dekker went about their work here with professionalism and class, and we wish them the best.
"At the same time, we're very pleased to bring Delly back to Cleveland and want to welcome John Henson as well. This deal satisfied several important aspects for us in terms of having both long- and shorter-term benefits and assets involved. We will continue to look for ways to improve and strengthen our position for the future, while enhancing our ability to compete and grow in the short term also."
The first-round pick that Milwaukee sent to the Cavs has lottery protections and might not convey until as late as 2024 because the Bucks owe a future first-rounder to the Phoenix Suns that might not convey until 2021.
The deal could save the Bucks about $19 million next season if they don't keep Hill, who has only $1 million of a $19 million deal guaranteed. Both Henson and Dellavedova, who won a title with the Cavs in 2016, have one year and about $10 million left on their contracts.
Milwaukee has several major free agents next summer, including Khris Middleton, Eric Bledsoe and Malcolm Brogdon. The three-team trade puts the Bucks in a better financial position to keep their team intact.
Hill, 32, is averaging 10.8 points per game and shooting 46 percent on 3-pointers, though he missed 11 games with a shoulder injury. Smith, 32, who is in the final year of his contract, has played in just 12 games this season, averaging 3.7 points and shooting 40 percent from 3-point range.
"We're excited to welcome George and Jason to the Bucks organization," general manager Jon Horst said. "George provides us added depth and experience at the guard position, while Jason gives us another frontcourt player who can stretch the floor."
Bucks star Giannis Antetokounmpo praised Hill as "a great point guard" while lamenting the loss of Henson and Dellavedova.
"Just not having John Henson here, it feels weird, I am not going to lie," Antetokounmpo said. "And especially Delly, he's one of the best teammates I've ever had. Great leader. Even though things weren't going as well for him, he was always positive, always trying to talk to all the guys and keep his spirit up and good."
Milwaukee coach Mike Budenholzer said he is excited to reunite with Hill, who spent the first three seasons of his career with the San Antonio Spurs, where Budenholzer was an assistant.
"Another guard that can kind of play both positions, that can attack off the dribble, shoots the 3-pointer at high percentage," Budenholzer said of Hill. "Defensively I think he can guard multiple positions. I've been around him a lot ... so there's a great comfort level."
The deal came together Friday in time for teams to be able to repackage players in other trades before February's trade deadline. That was an impetus for getting the deal done now. The Cavs have been aggressive in looking to move out veterans for future picks, now having acquired four future selections in the past 10 days, including a trade that sent Kyle Korver to the Utah Jazz.
Henson, 27, hasn't played in a month, recently had wrist surgery and is expected to miss several months. Dellavedova, 28, has been limited to 12 games this season due to an ankle injury and is averaging a career-low 1.7 points.
"I'm glad my Aussie brother is back," Cavs center Tristan Thompson said of Australia native Dellavedova following a 129-110 loss to Sacramento. "Brings us veteran leadership, a guy that's won before, a guy that's going to push Collin [Sexton], control the game for the second unit and he'll make shots. He's good at throwing lobs to me, so I'm really happy about that.
"I think it will be good for our team, not just for myself, but for our team."
Sexton, the No. 8 overall pick in the June draft, has already heard stories about Dellavedova.
"Everybody said he's a real good guy, a real good locker room guy," Sexton said. "We lost George, which was my vet, so I'll have to talk to Dellavedova and he'll be able to lead me how George led me. They say he practices hard too, so we're going to have some battles."
Dekker, who starred at Wisconsin before becoming the No. 18 overall pick in 2015, has been out for more than a month with an ankle injury. The 24-year-old has played only nine games.
"This trade allows us to continue to work to improve our team and gives us a young, developing player in Sam whose versatility and athleticism at the forward position will allow him to earn an opportunity to contribute," Wizards president Ernie Grunfeld said. "We wish Jason the best moving forward and appreciate the value he brought to our team as a great teammate and true professional."
ESPN's Bobby Marks, Ohm Youngmisuk and Malika Andrews, and The Associated Press contributed to this report.