Ambassador Theatre, Ambassador Theater, or Ambassadors Theatre may refer to:

United States

• Ambassador Theater (Baltimore, Maryland)
• Ambassador Theater (Washington, D.C.)
• Ambassador Theatre (New York City)
• Ambassador Theatre (St. Louis)

Elsewhere

• Ambassador Theatre (Dublin), a former cinema, now an events venue
• Ambassadors Theatre (London), a small West End theatre
• Ambassadors Theatre (Perth), a former cinema and theatre in Perth