Holy See and the United Nations
The Holy See is not a member of the United Nations (not having applied for membership) but was granted permanent observer state (i.e., non-member state) status on 6 April 1964. In that capacity, it has the right to attend all sessions of the United Nations General Assembly, the United Nations Security Council, and the United Nations Economic and Social Council to observe their work.
Source: Wikipedia — Holy See and the United Nations (CC BY-SA 4.0)