Ulster Grand Prix Clerk of the Course, Noel Johnston, said he was delighted Johnson had been confirmed for the final major international road race of the season.
“It's great to have Gary back at Dundrod and he'll ride a Superbike for Clive Padgett.
“He's still trying to get bikes sorted for the Supersport and Superstock races and I'm confident he'll have something in place one way or the other,” said Johnston.
“Gary is a top rider and he'll be one of the big contenders at this year's Ulster Grand Prix.
“We're all set and ready to go from an organisational point of view and we're looking forward to some more fantastic action at Dundrod.”
Johnson made it onto the rostrum in third place in the Superstock race at last year's Ulster GP.
He also finished fourth and sixth in the Superbike races and fifth in the Supersport class.
The Broughton man joins a quality international line-up that includes Ulster's Michael Dunlop – a hat-trick winner at the UGP in 2011 – plus his brother William on the Craig Honda machines and Tyco Suzuki duo Guy Martin and Conor Cummins.
Evergreen Kiwi Bruce Anstey showed at the TT that he remains as competitive as ever and the popular New Zealander will be aiming for a repeat of his Superbike success at Dundrod 12 months ago on Clive Padgett's Fireblade.
KMR Kawasaki's Ryan Farquhar will sit out the 600cc class but is a definite starter in the Supertwin 650 races.
The 36-year-old has yet to decide whether or not to compete in the Superbike and Superstock races.