Adding to a strengthened squad, Dunne will bring a lot of experience and quality under his belt, having previously played with Sheriff YC, St Patrick's Athletic and Dundalk.
Speaking to club PRO Daniel Pitcher, manager Brian McCarthy says he's delighted with his new signing.
"I'm delighted to be able to bring Keith to Porterstown, he like everyone else will have to train hard to get into the team but I am confident he will have an impact at the club."
However in response to inaccurate recent reports that the manager is signing new batches of players as he sees fit, McCarthy insists that's not true.
"As great as it has been to have been in a position to sign players to the club, we had to respond quick after we lost ten in the season break."
"Only there recently, we have lost Eamon Moylan and Josh Douglas, who've gone to Home Farm."
"Then another of the new summer signings Aidan Downes, has been out recently with a knee injury."
"The players we have brought to Mochta's were not brought out of spite, I have signed them because there are places I need to have covered as a result of those who have left."
" With the great new signing in Keith Dunne, I stress that he comes here to try and fill a space, I'm delighted to have him and I'm sure the Mochta's support will be too." Brian Said.