- Acting for Two: Robert Vaughn, David McCallum and Leo G. Carroll all got to play two roles ("The Double Affair," "The Gurnius Affair" and "The Bow Wow Affair" respectively), while Diana Hyland played a politician's wife and her THRUSH-sponsored double in "The Candidate's Wife Affair" and Joan Collins was a saloon entertainer and a countess in "The Galatea Affair." But H.M. Wynant took home the gold for playing quadruplets in "The Prince Of Darkness Affair."
- Company Hop: The TV show was made by Metro-Goldwyn-Mayer, but the TV movie The Return Of The Man From U.N.C.L.E. was done by Viacom.
- Fake Russian: Scotsman David McCallum cast as Russian Illya Kuryakin.
- Recycled Set: Entire drinking games could and probably have been based around this.
- Referenced by...: The title of At the Drive-In's song "Napoleon Solo" is a reference to the main character of this series, though it's unrelated lyrically (it's a Grief Song for two friends of the band who died in a car crash).
- Star-Making Role: For David McCallum.
- Unintentional Period Piece: The series lives and dies on its Cold War setting, and the oddity of a spy organization employing both American and Soviet agents.
- You Look Familiar: Guest stars were frequently recycled in unrelated roles.
- The all time champion of the series is probably character actor Woodrow Parfrey, who had 5 guest appearances in unrelated roles in the first three seasons.