Butler has been in a dispute with Minnesota Timberwolves this season after requesting a trade during the summer.
However, no team initially proved willing to meet the Timberwolves’ demands to part ways with the 29-year-old shooting guard.
Butler has featured in 10 games so far this term as Tom Thibodeau’s team have gone 4-9.
However it has now been widely reported that he has agreed a switch to the Sixers, trading the Western Conference for the Eastern.
James made a high-profile trade himself during the summer, moving from Cleveland Cavaliers to LA Lakers.
The four-time MVP has struggled to replicate his Cavs form in Los Angeles with the Lakers currently 5-6 for the current NBA season.
Butler had made a point of playing against the Lakers this year, despite missing some matches.
But LeBron James believes his move makes the Sixers a much stronger team, while revealing that Butler was unhappy in Minnesota.
“I mean, obviously we all know what’s been going on in Minnesota with Jimmy from the beginning,” James said.
“So I guess they both feel – I mean I think it’s good for both sides, I guess. They weren’t happy, Jimmy wasn’t happy.
“I think [Philadelphia] were a contender before. It only enhances what they are able to do.
“They’ve got Ben [Simmons] and Joel [Embiid] and now you add in Jimmy, I think that is going to be a very, very good team.”
The trade should not be such a shock with Butler having blasted his Timberwolves team-mates following a defeat earlier this season.
“I don’t believe in luck,” he said.
“I think everything happens for a reason. We played good, four games. We played bad, eight games.”