QPR boss Neil Warnock is yet to make a move in the transfer market since winning promotion to the Premier League and is now stepping up his bid to bring in new recruits.
Warnock revealed earlier on Thursday that he expected to sign a 'few new players' over the next couple of weeks and has made an offer for Campbell.
The forward enjoyed an impressive campaign in the top flight last season as he scored 13 goals during Blackpool's ultimately unsuccessful battle to avoid relegation.
Campbell has a clause in his contract allowing him to leave Bloomfield Road for £1.25m and QPR are understood to have met that figure.
However, QPR may yet face competition for the former Birmingham City frontman with several clubs understood to be keen on Campbell.
Fulham, Stoke City and Sunderland have all been linked with offers, but QPR will hope to win the race for his signature.