Wells failed to start a game for the Clarets after signing from Huddersfield Town in January.
QPR manager Steve McClaren said: "I am delighted with Tomer and Nahki now too, to join him.
"I know them very well, they are a nightmare to play against! I am glad to have them in our squad.
"They are two very good strikers with great pedigree and experience.
"Nahki is proven, he scores goals. He's scored goals at this level, he has played in a team which has secured promotion, so he's someone who has been there and done it.
"That is exactly what we need."