The Parliament of Southern Ireland was set up under the Government of Ireland Act to legislate for Southern Ireland. A Parliament of Northern Ireland was set up to legislate for Northern Ireland. The Parliament of Southern Ireland consisted of two houses:

• House of Commons of Southern Ireland
• Senate of Southern Ireland

The parliament had a brief tenure, as the Government of Ireland Act was passed in 1920 creating the bodies, while the Irish Free State constitution was established in 1922, ending those same institutions.