Chloramphenicol is a bacteriostatic antimicrobial originally derived from the bacterium Streptomyces venezuelae, isolated by David Gottlieb, and introduced into clinical practice in 1949.

It was the first antibiotic to be manufactured synthetically on a large scale. Chloramphenicol is effective against a wide variety of microorganisms; it is still very widely used in low income countries because it is exceedingly cheap, but has fallen out of favour in the West due to a very rare but very serious side effect: aplastic anemia.

In the West, the main use of chloramphenicol is in eye drops or ointment for bacterial conjunctivitis.