2O or 2-O may refer to:
2o Sector, see Secondary sector of the economy 2'-O-methylation 2O, IATA code for Island Air Service in Alaska; see Essential Air Service
See also 2OOO, a Sydney, Australia radio station O2 (disambiguation) H2O (Molecule) J20 (disambiguation) L20 (disambiguation) N2O (disambiguation) 20 2O (Atom) 2Q (disambiguation)