The Department of Immigration and Border Protection (DIBP) was a department of the Australian Government that was responsible for immigration, citizenship and border control (including visa issuance). In 2017, the organisation was subsumed into the Department of Home Affairs, which combines its responsibilities with a number of other portfolios.

The last departmental head was Secretary Michael Pezzullo, who reported to the then-Minister for Immigration and Border Protection, Peter Dutton, and the Assistant Minister for Immigration and Border Protection, Alex Hawke.

The Department of Immigration and Border Protection was formed by way of an Administrative Arrangements Order issued on 18 September 2013 and replaced the majority of the functions previously performed by the former Department of Immigration and Citizenship; with the exception of most settlement and multicultural affairs programs that were assumed by the Department of Human Services. Additionally, the Australian Border Force and associated policy was assumed by the Department of Immigration and Border Protection (previously managed under the authority of the Attorney-General's portfolio), a move intended to ensure stronger integration of border protection resources.

Following Federation in 1901, immigration to Australia was handled by the Department of External Affairs. In 1916 responsibility shifted to the newly created Department of Home and Territories. Migration was handled from 1928 until 1932 by a recreated Department of Home Affairs and from 1932 until 1945 by the Department of the Interior, except that between January 1925 and January 1928 Victor Wilson and Thomas Paterson were Ministers for Markets and Migration.

In July 1945, the Department of Immigration was established as Australia launched a massive immigration program following World War II. The then Minister for Immigration, Arthur Calwell promoted mass immigration with the slogan "populate or perish". Since 1945, the department's names, functions and responsibilities have changed several times.

The present departmental title, Department of Home Affairs, refers to a combined department covering law enforcement, national and transport security, criminal justice, emergency management, multicultural affairs and immigration and border control. Departmental writing guide mandates the use of "Home Affairs" as a shortened form of the Department's name. ^{[citation needed]} DHA is exclusively used by Defence Housing Australia.^{[citation needed]}

Over the years, the department has been the centre of controversy in regards to the Australian Government's policies of mandatory detention of unauthorised arrivals, the Pacific Solution, and the treatment of asylum seekers that was criticised in the Palmer Inquiry reports in 2005.

The Rudd Labor government announced the end of mandatory detention in Australia in July 2008, unless the asylum seeker was deemed to pose a risk to the wider community, such as those who have repeatedly breached their visa conditions or those who have security or health risks.^{[citation needed]}