The 29 year-old, who arrives on a free transfer following his release from Chelsea, becomes Mark Hughes' eighth summer signing.
Bosingwa's signing comes too late for him to take part in Saturday's season opener against Swansea at Loftus Road.
However, manager Hughes hailed the arrival of the double Champions League winner and told the club's official website: "I am delighted to bring a player of his undoubted quality to the club. He has got plenty of pace, great technical ability and all the attributes you need to be a top player.
"Jose has a lot of versatility which is something I like my players to have. He can operate right across the back and can also play the holding role in midfield.
"He's another Champions League winner, the third in the squad now with Park Ji-sung and Djibril Cisse, and will add invaluable experience to the group.
"His experience is really important to us. He understands the Premier League and he understands what it takes to win games. He has got a winning mentality and that is what I want to have around the place."
Bosingwa's first taste of Champions League success arrived with Porto in 2004, before enjoying further glory with Chelsea last season following their penalty shoot-out success over Bayern Munich.
His overall medal haul includes 15 trophies, including four Portuguese league titles, one Premier League title and three FA Cup successes.
The Rs' latest summer signing told qpr.co.uk: "I'm really pleased to be here. I had the pick of many clubs, but the project here excites me greatly.
"I spoke yesterday with the manager and owner and they showed me what they want for the future of the club.
"I played for Chelsea for four years and I love Premier League football and the supporters. It is fantastic for me to stay in England. I'm happy and all of my family are happy, and that is most important.
"This is maybe the most important challenge of my career. I want to help my team-mates and the team with my experience.
"Now I am a QPR player, I will give my best - for the team and for the supporters.
"All together, we will fight for the club. We need time. We start now and in one, two or three years we can win something. We have to have passion and I think the results will come."
Chairman Tony Fernandes believes the arrival of Bosingwa is indicative of the progress the west London club have made.
"I think it speaks volumes of how far we've come as a club that we're able to attract a double Champions League winner to Loftus Road," he said.
"There was big competition from a number of Europe's top clubs - including a few from the Premier League - for his signature, so I couldn't be more delighted that we've managed to get him here.
"Mark (Hughes) and (scout) Mike (Rigg) are dovetailing superbly together to improve our squad and this latest addition excites me as much as the seven that have preceded it."