Proclamation Day is the name of a number of official or unofficial holidays or other anniversaries which commemorate or mark an important proclamation. In some cases it may be the day of, or the anniversary of, the proclamation of a monarch's accession to the throne. A proclamation day may also celebrate the independence of a country, the end of a war, or the ratification of an important treaty.

Proclamation Day is the South Australian public holiday that celebrates the proclamation of South Australia as a British province. The proclamation was made by Captain John Hindmarsh, beside The Old Gum Tree at Glenelg, on 28 December 1836. The proclamation included the same protection under the law for the local native population as for the settlers. It is now a public holiday in South Australia, although this holiday is held on the first otherwise working day after the Christmas Day public holiday (usually 26 December).^[1] Formal ceremonies and celebrations are always held on 28 December.