OTH may refer to:
Optical Transport Hierarchy, in telecommunications Other than honorable discharge, a US military discharge Over-the-horizon radar Over the horizon boat, a type of cutterboat in the U.S. Coast Guard. Airport code for Southwest Oregon Regional Airport Our Tampines Hub, a community building, Singapore Opportunity to hear, a term used in radio advertising. One Tree Hill (TV series), a 2003–2012 American drama series.
See also 0th (i.e. "zeroth")