IMHO is an acronym for "In My Humble Opinion" or sometimes "In My Honest Opinion". It often appears in emails, mailing lists, text messages, and other electronic forums where abbreviations and acronyms are used to speed message composition and to save space.

Variants include IMO for "In My Opinion", IMAO for "In My Arrogant Opinion" or "In My Awesome Opinion" and IMNSHO for "In My Not So Humble Opinion". Users of the variants often maintain that the phrase IMHO is self-contradictory, because no one who posts to an electronic forum is humble.