The Blues have agreed a fee for the transfer of the Porto right-back or winger, who is now in England undergoing a medical. He has yet to agree personal terms.
A statement on Chelsea's official website read: "Chelsea can confirm it has reached agreement with FC Porto for the transfer of Jose Bosingwa. The player is now in England to discuss personal terms and undergo a medical."
The player is likely to sign a five-year contract at Stamford Bridge and Chelsea will pay around £16million for his services.
His arrival will place more speculation on the future of Julian Belletti. He has been ignored in recent weeks with Michael Essien playing at right-back.
Chelsea's other right-back, Portugal international Paulo Ferreira, signed a five-year deal earlier this season and is unlikely to move on.
United have long been in the hunt for a right-back and assistant coach Carlos Queiroz confirmed their interest in the player earlier in the season.
United saw him as a successor to Gary Neville but Chelsea have moved swiftly to snap-up the attack-minded defender.
Bosingwa is set to play for Portugal in the Euro 2008, but was born in Kinshasa in the Democratic Republic of Congo.