Delaney, who takes up his post with immediate effect, will join the Exiles from Championship club Nottingham, where he spent seven years as rugby director.
Former Irish coaches Toby Booth and Neal Hatley recently left the Premiership outfit to take up posts at Bath.
Delaney had three seasons with Irish as a player, featuring in the second-row, before being appointed Nottingham's rugby director for the 2005-06 campaign.
"It is great to be returning to London Irish," he said.
"I enjoyed plenty of good times with Irish as a player, and I am sure I will experience the same as a coach."
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The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
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Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
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The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
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The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.
