Oe or OE may refer to:
The Organisation for Economic Co-operation and Development (OECD; French: Organisation de coopération et de développement économiques, OCDE) is an intergovernmental economic organisation with 35 member countries, founded in 1961 to stimulate economic progress and world trade.
The Oedipus complex is a concept of psychoanalytic theory. Sigmund Freud introduced the concept in his Interpretation of Dreams (1899).
Oedipus (US: , UK: ; Greek: Οἰδίπους Oidípous meaning "swollen foot") was a mythical Greek king of Thebes.
The Oerlikon GDF or Oerlikon 35 mm twin cannon is a towed anti-aircraft gun made by Oerlikon Contraves (renamed as Rheinmetall Air Defence AG following the merger with Rheinmetall in 2009).
Oenothera is a genus of about 145 species of herbaceous flowering plants native to the Americas. It is the type genus of the family Onagraceae.
The Oerlikon 20 mm cannon is a series of autocannons, based on an original German 20 mm Becker design that appeared very early in World War I.