Rabosky fills the role vacated by Mike Folino, who moved to DDB Chicago in June last year.
Brian Morris, the chief executive of Dailey & Associates, said: "Steve will provide us with immediate creative leadership and a new level of credibility. It signals that we're serious about our next chapter."
Rabosky, who left Saatchis in August last year, won a gold Lion at Cannes in 2004 for the Toyota Tacoma "girlfriend" ad. Before Saatchis, he worked at TBWA\Chiat\Day in California.