Making his first start of the year and seeking his first PGA Tour win in almost four years, Scott stormed into a share of the 54-hole lead at the Genesis Invitational in Los Angeles on Saturday.
Three back-nine birdies, including one on his last hole, rounded out a third-round 67 that lifted Scott to a 10-under-par total.
He was joined in the lead on that mark by McIlroy (68) and Kuchar (70) and the three will comprise the final group at Riviera Country Club.
Russell Henley (68) and Harold Varner (69) are tied for fourth at nine under.
Former World No.1 Scott, who won at Riviera in 2005, is seeking to end a US Tour title drought that stretches back to March 2016.
But family commitments were keeping the Queenslander from thinking too much about lifting the trophy at the Tiger Woods-hosted invitational event on Sunday.
"It's likely a room service night and it's actually my daughter's (fifth) birthday, so I'll speak to her before she goes to bed on the east coast," Scott told AAP.
"I think I'm in a good place (on the leaderboard). Controlling your thoughts is much more difficult when you're two shots ahead, as opposed to sitting among a pack of players like I am now.
"I'm not really getting myself too flustered about what position I'm in. I feel quite comfortable."
Scott birdied the final hole in round three at Riviera CC. PHOTO: Katharine Lotze/Getty Images.
Scott, who also has two runner-up results at Riviera, began his round ominously with a disappointing par at the reachable par-5 opening hole before a bogey on the 2nd.
However, four birdies in a five-hole stretch starting at the 7th kick-started his charge.
He played the back nine patiently before firing an approach to the 18th green to nine feet and converting to ensure he plays in the final group at Riviera for a second-straight year.
While it's a long time since his last US win, Scott is coming off a victory in his last start at the Australian PGA Championship late last year.
Despite the break, he feels prepared for a battle with Kuchar and in-form McIlroy, who won four US Tour titles last year including the elite Players Championship.
"It will be fantastic. I love watching him play," Scott said of four-time major winner McIlroy.
"He's certainly one of the benchmarks of the game at the moment and it will be good for me to see how I stack up.
"Hopefully, I can get the better of everybody tomorrow."
Marc Leishman was the only other Australian to make the weekend and his 68 elevated him to three under.
Event host Tiger Woods capitulated with a 76 that dropped him to five over.
- Evin Priest, Australian Associated Press