The word hemlock may refer to:
- Conium, or more specifically, Conium maculatum, a common European herb that contains the alkaloid coniine and was probably the state poison of Ancient Greece, and the purported poison used in the execution of Socrates.
- Several other poisonous plants in the family Apiaceae (formerly Umbelliferae) are sometimes called hemlock:
- Tsuga, a genus of conifers originally named "hemlocks" due to a perceived similarity in the scent of the crushed foliage to that of Conium.
- Hemlock Society, a group advocating assisted suicide
- Hemlock (company), a chemicals manufacturer specializing in silicon products
- Hemlock, a variant of the Emacs text editor for Unix
- Hemlock Records, a record label based out of Chicago, Illinois
- Hemlock is a heavy metal band from Las Vegas, Nevada
- Hemlock is a 1990s punk band from San Diego, California
- Hemlock was also the name of a black metal project by bass player Dan Lilker
- Sherlock Hemlock, the name of a Muppet detective
- Hemlock (play), an original play by playwright Bob Jude Ferrante
- Hemlock's Diary is a political, economic and social blog written in Hong Kong
- Hemlock, an Iranian movie also released as Shokaran and starring Hediyeh Tehrani
- Hemlock, a fictional Russian assassin in JAG