Ukraine is among the original Member States of the United Nations
Background
The United Nations Member States list records Ukraine with the entry "Date of Admission: 24-10-1945".
That is the date the Charter of the United Nations entered into force, so Ukraine is among the original Member States.
Ukraine is also a member of the Council of Europe, the World Trade Organization and the Organization for Security and Co-operation in Europe.
Ukraine is not a member of the North Atlantic Treaty Organization and is not a member of the European Union; it holds EU candidate status.
Ukraine joined the International Bank for Reconstruction and Development in September 1992 and the International Development Association in May 2004.