The 55-year-old Blake enjoyed a lengthy playing career in rugby league in Australia and has coached in both codes, including a previous spell with Leicester.
London-born Blake played rugby league for Australia Schools and then with clubs including Manly-Warringah, South Sydney and Auckland Warriors, ending his first-class career with 138 tries in 261 games. He also played in the State of Origin series with New South Wales.
An extensive coaching career included a spell at South Sydney Rabbitohs before a switch to rugby union where he has worked with Southern Districts and Western Force, as head coach at Manly and as defence and skills coach to Australia’s national squad before moving to England with Tigers and then Wasps.
Leicester Tigers head coach Murphy said: “It is no secret that we’ve been looking for the right person to come in and add to what we already have in the coaching team.
“We know Phil well, he knows what the club is all about and we believe he has a lot to offer in terms of experience and his all-round knowledge of the game.