OTH

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.