It was established by the UN Educational, Scientific and Cultural Organization (UNESCO) in 2010.
The date coincides with the day in 1973 that the General Assembly of the United Nations adopted Arabic as the sixth official language of the Organization.
It was seeking "to celebrate multilingualism and cultural diversity as well as to promote equal use of all six of its official working languages throughout the organization".
In July 2022, UN Swahili Language Day (July 7) was created.
Portuguese and Swahili are the only non-official UN languages to have a UN Language Day.