Lock Horwill led the Reds to this year's Super Rugby title and has also been Australia's form forward in their past two Tri-Nations Tests.
As expected, 92-Test back Matt Giteau was a notable omission, with Deans instead selecting NSW playmaker Berrick Barnes as the five-eighth back-up to Quade Cooper and Melbourne halfback Nick Phipps as a third specialist halfback.
Bulldozing No.8 Wycliff Palu (shoulder-knee) heads a list of six wounded Wallabies stars who have been named despite being grounded by injuries, with Palu out for most of the past two seasons.
Deans also selected hooker Tatafu Polota-Nau (knee), prop James Slipper (ankle) and Drew Mitchell (ankle) who are also yet to return to action after injury.
Waratah backs Barnes (concussion) and centre Rob Horne (elbow) were included after recently making comebacks in club rugby after playing little Super Rugby this season.
Western Force flanker Matt Hodgson, who has been the back up for ball scavenger David Pocock, is arguably one of the most unexpected omissions after being among the Test squad for the past three years.
Wallabies World Cup squad:
Backs - Kurtley Beale, James O'Connor, Drew Mitchell, Digby Ioane, Adam Ashley-Cooper, Rob Horne, Pat McCabe, Anthony Faingaa, Berrick Barnes, Quade Cooper, Nick Phipps, Luke Burgess, Will Genia.
Forwards - Ben McCalman, Radike Samo, Wycliff Palu, David Pocock, Rocky Elsom, Scott Higginbotham, James Horwill (capt), Rob Simmons, Nathan Sharpe, Dan Vickerman, Ben Alexander, Sekope Kepu, James Slipper, Salesi Ma'afu, Stephen Moore, Saia Faingaa, Tatafu Polota-Nau.
- AAP
