Everton announced that the 41-year-old had taken up a post at Goodison Park that will also see him eligible to play for the second string.
And with reserves boss Alan Stubbs short of defenders, Weir went straight into the side for Tuesday afternoon's 'mini-derby' at Liverpool.
Weir left Rangers last month to pursue other options and, after training with Sheffield United, has now taken up an opportunity to begin his coaching career with Everton's reserve and Academy players.
The veteran Scotland international made 269 appearances during an eight-year spell at Goodison before leaving to join the Ibrox club five years ago.
Toffees manager David Moyes told the club's website, www.evertonfc.com: "David's returning to us in a coaching capacity.
"He will help out Alan Stubbs with the reserves and he will also play in the occasional reserve game to help support some of those younger players coming through.
"It will be good to have him around the place. He is a great professional and someone all the players at the club can look up to.
"He did great for us when he was a player here and we are looking forward to being able to work with again as he starts out in his coaching career."
Source: PA
Source: PA