The 33-year-old, who has been capped 22 times by his country, was available on a free transfer after his contract Lecce expired at the end of last season.
And Chevanton, who has trained with the Rs recently, hopes to make an impact at Loftus Road with the club currently top of the Championship.
|6/4||QPR are 6/4 with Coral to win the Championship
"I am really looking forward to the challenge of playing in England. I have scored goals all around Europe and I am confident I can continue that record with QPR.
"When I was younger, I loved watching English football. The atmosphere here is great and when the chance came to join QPR, it was all I wanted.
"I have a great will-to-win and I can’t wait to do my best for the club and fall in love with the fans."
Redknapp revealed recently he was tracking a new striker following injuries to front pair Bobby Zamora and Andy Johnson, and is confident Chevanton can aid the club's promotion push.
"With the injuries we’ve had to Bobby and AJ, we’re really short of options in that department," Redknapp said.
"Javier has spent time with us and integrated into the group very well. He arrives with a good pedigree and gives us a much-needed extra option in attack."