Kilduff, who scored 19 goals in all competitions in the 2010 season, returns to the Hoops for his second spell at the club.
The highly-rated young striker was previously involved in the youth section at Rovers, before moving to UCD at the start of the 2009 season.
Hoops boss, Michael O’Neill said: “Ciarán is another one of the talented, young players we had in our sights to bring to the club for the coming season, and I’m delighted to have secured his services.
“Along with Gary Twigg, we now have two of last season’s three top scorers. The profile of players like Ciáran, and the players we signed last weekend, is very important to us. They are young, talented players who are very keen to prove themselves in the game.”
Kilduff is also really looking forward to linking up with the Hoops squad. He said: “I’m delighted to be going back to Shamrock Rovers, and am really looking forward to working with Michael (O’Neill). I think he is glad to have me, and I’m definitely glad to have signed.
“I enjoyed my time at UCD; winning the first division in my first year there, and consolidating the place in the premier division last year. But I think football is all about timing, and I think this is the right time for me to be playing at a club like Rovers.”