Chicago will also be sending a 2023 second-round pick to Washington.
The move sheds Washington of significant salary, as Porter is owed $26 million this season and $27.2 million in 2019-20. He also has a $28.4-million player option for 2020-21.
Parker has a team option worth $20 million next season, while Portis will hit restricted free agency. The trade also drops the Wizards' tax bill from $8.96 million this season to $3.34 million.
Wizards owner Ted Leonsis recently said in an interview with local radio station WTOP that the team wasn't going to be dealing Porter, Bradley Beal, or John Wall ahead of this Thursday's trade deadline, according to NBC Sports' Lisa Redmond.
Porter has spent his entire six-year career with the Wizards after they selected him with the third overall pick in the 2013 draft. His production has dipped across the board following a breakout 2017-18 campaign, as he's averaging 12.6 points, 5.6 rebounds, and 1.6 steals on 45.7 percent shooting in 29 minutes per game.
Parker's first and only season with the Bulls was a massive disappointment. The 23-year-old forward fell out of the rotation in early December before working his way back to a reserve role last month. He contributed 14.3 points and 6.2 rebounds across 39 appearances.
"I came here because I’m a city kid. I do it for the fans. I tried to do everything I could to show them that I appreciated the city," said Parker once news of the trade broke, according to the Chicago Tribune's K.C. Johnson.
Portis was one of the longest-tenured members on the Bulls, averaging a career-best 14.1 points on 45 percent shooting this season.