"I Won't Let You Down" is a song by British band Ph.D., released as the second single from their eponymous debut studio album (1981).

The original music video for the song was set in and around the Queensway area of West London.

As with the band's previous single "Little Suzi's on the Up", the video is shot in a slapstick comedy style and features Jim Diamond as a well-dressed man trying to win back the affections of his lover (played by Nina Carter) (thus mirroring the theme of the song) using presents and taking her to upmarket bars and restaurants.

Tony Hymas appears as the video's antagonist; in various scenes dressed in various disguises he makes unsuccessful attempts to assassinate, or maim Diamond's character in order to win the affections of the woman.

He is finally successful when, posing as a car dealer, he lures Diamond into a second hand car, which is revealed to be on the end of a crane in a scrapyard being lifted up, whilst Hymas walks away with the girl as the camera zooms out and fades to black.