Broomfield, who was in charge of Redknapp's scouting operations at both Portsmouth and Tottenham, replaces Mike Rigg and will be in charge of identifying transfer targets as well as working closely with the academy.
Speaking to the club's official website, Broomfield said: "I've worked closely with Harry for a number of years now, so it's great to link up with him again.
"A scouting job is 24/7 and I've never really had a break for 25 years, but I left Spurs in September and I'm refreshed and looking forward to working back in football.
"The opportunity to work with Harry again was ideal.
"When I spoke to the hierarchy at the club about the plans they have to take QPR forward, it sounded like the kind of project I wanted to be part of."