The Tyco BMW rider, who was injured in a 130mph crash at Ireland's Corner last August, also sat out this year's North West 200 and Isle of Man TT.
Gary Dunlop will make his debut with his father's famous number three plate.
"I've never let anyone since Joey ride as number three but who better to use it than Gary," said clerk of the course Noel Johnston.
"I think it'll be pretty special to see it on the grid after all these years."
Joey Dunlop won a record 26 Isle of Man TTs and 24 Ulster GPs before he was killed in a crash while racing in Estonia in July 2000.
Michael Dunlop and Ian Hutchinson both return to Dundrod gunning for the top step of the podium with Dean Harrison, Ivan Lintin, Lee Johnston, William Dunlop, Peter Hickman, Bruce Anstey, Dan Kneen, Conor Cummins and Christian Elkin among the 173 entries.
Johnston said the absence of Martin, who will be in Utah filming a land speed record attempt, is "a shame, but in no way will there be any less of a spectacle for the fans".
He added: "I'm very pleased with the final entry list and think it says a lot about the popularity of the event that the total number of entries are growing year on year, as is the number of newcomers [54] coming to Dundrod."
Martin has presented a number of TV programmes in recent years, most notably Channel 4's Speed with Guy Martin.
The 2016 Ulster Grand Prix will run between August 8 and 13.
Guy Martin will not be racing at next month's Ulster Grand Prix because of TV commitments in America.