"I'm in Marsport Without Hilda" is a short story by Isaac Asimov. The story first appeared in the November 1957 issue of Venture Science Fiction Magazine, and was reprinted in the collection Nine Tomorrows in 1959, in a bowdlerized version. The complete original version appeared in Asimov's Mysteries (1968). Mildly ribald, it is a mystery story in a science fiction setting.

A Galactic Service agent, Max, is in Marsport without his wife, Hilda, for the first time in a long time. He plans to visit a beautiful and accommodating woman of his acquaintance named Flora, but his plans are disrupted when he receives an unexpected assignment. His supervisor informs him that a new source of altered Spaceoline has appeared. While regular Spaceoline is a common anti-nausea treatment, a chemical modification can turn it into a dangerous narcotic. The Service suspects that one man in a group of three VIPs is smuggling the drug.