At this time, Levant was becoming best known to American audiences as one of the regular panelists on the radio quiz show "Information Please". Originally scheduled as a guest panelist, Levant proved so quick-witted and popular that he became a regular fixture on the show in the late 1930s and 1940s, along with fellow panelists Franklin P. Adams and John Kieran and moderator Clifton Fadiman. "Mr. Levant," as he was always called, was often challenged with musical questions, and he impressed audiences with his depth of knowledge and facility with a joke. Kieran praised Levant as having a "positive genius for making offhand cutting remarks that couldn't have been sharper if he'd honed them a week in his mind. Oscar was always good for a bright response edged with acid." Examples include "I knew Doris Day before she was a virgin," "I think a lot of Bernstein—but not as much as he does," and (after Marilyn converted to Judaism when she married playwright Arthur Miller), "Now that Marilyn Monroe is kosher, Arthur Miller can eat her."