As part of the trade, the Jets get 21-year-old forward Marko Dano plus a first-round draft pick this June and another conditional pick.
"It's a great acquisition," Blackhawks coach Joel Quenneville said. "There's a lot of familiarity. I'm sure his old teammates are pretty excited in a lot of ways. He brings the intangibles that you look for. He knows his way around our team. I'm sure he's excited to come to Chicago as well."
The conditional pick the Jets received is a 2018 third-round choice if the Blackhawks win the Stanley Cup this season, a source told ESPN.
Ladd, who can become an unrestricted free agent July 1, returns to the team with which he won the 2010 Stanley Cup. Salary-cap issues prompted the Blackhawks to then trade him to the Atlanta Thrashers, which relocated to Winnipeg in 2011.
"I knew that it was a probability that I was going to end up being traded and I think Chicago was on the top of my list for places I wanted to be,'' Ladd said on a conference call. "I''m familiar with the organization and guys already on the team and that would ease the transition for me.''
Ladd will play on the left side of Chicago's top line, filling a giant hole created by the trade of Brandon Saad to Columbus last summer. Andrew Shaw had done a solid job in the role of late, but the trade for Ladd moves Shaw down to a lower line and creates more balance for the defending champions.
"Regardless of who I play with, going to a team that has a chance at winning the Stanley Cup is an exciting prospect for anyone,'' Ladd said.
Fraser and Harrison will report to the American Hockey League's Rockford IceHogs, the Blackhawks said in a statement.
Dano, considered one of Chicago's top prospects, was acquired from Columbus in the Saad deal last summer. But he was sent down to Rockford on Dec. 11.
Ladd also won the Cup with the Hurricanes in 2006, two years after he was drafted by Carolina in the first round.
The 11-year NHL veteran and British Columbia native has 202 goals and 252 assists in 750 career NHL games.
"He brings so much to the table," Blackhawks general manager Stan Bowman said of Ladd. "Just his competitiveness. He's a very versatile player. He's played a big role in Winnipeg the last few years there. On their team, he does it all."
Ladd recorded a career-high 62 points, with 24 goals and 38 assists, in 81 regular-season games with the Jets last season.
The Blackhawks, trying for their fourth NHL title in the last seven seasons, were on the lookout for a left winger to play with Jonathan Toews on Chicago's top line. Ladd had been rumored for weeks to be on Chicago's trade deadline target list.
Thursday's deal might not be the last for Chicago before Monday's trade deadline. Sources told ESPN that Bowman also is interested in acquiring defensive help.
"The big thing for us is just the familiarity he has," Bowman said of Ladd. "Not just with our coaching staff, but our players. I think he's maintained a friendship with a number of our players, and that's important.
"There's still a few days to go," he added. "It's our job to continue to look and see if there's anything that makes sense to improve the team. If it doesn't change from where we are now, I really like the group we have."
Information from ESPN's Pierre LeBrun, Craig Custance and The Associated Press was used in this report.