QPR chairman Tony Fernandes said: "Harry was our number one target, the unanimous choice of the board and we're delighted we've been able to attract him to the club."
Fernandes continued: "He has a proven track record in the Premier League and has all the characteristics we were looking for to get us out of the current situation we find ourselves in.
"His man-management skills are second to none and we are confident he is the right man to lead us away from the bottom of the table."
A announcement regarding Redknapp's backroom team will be made in due course.
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Dry with clear spells overnight. Dry and breezy with sunny spells for much of tomorrow. Rain arriving later. Becoming humid from Monday.
Showers fading away with clear spells overnight. Dry with sunny spells for much of tomorrow with rain arriving later. Becoming humid later.
Feeling warm in this afternoon's sunshine. Breezy at times with the risk of an isolated shower.