Prime Minister Ahmed bin Dagher flew from Riyadh to the port city where he said upon arrival that his return is "final".
The premier's voyage is the first since his predecessor Khaled Bahah fled Aden in October last year after surviving a bombing attack, only weeks after he had returned with a handful of ministers.
Government forces backed by the Saudi-led coalition had pushed Shiite rebels and their allies out of Aden and four other southern provinces in the summer.
The coalition launched a military campaign against the rebels in March 2015 as they closed in on President Abedrabbo Mansour Hadi after he took refuge in Aden, forcing him into exile in Riyadh.
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Hadi has not made any suggestion of returning to Yemen soon.
Bin Dagher said his return follows a decision by Hadi to withdraw the central bank from rebel-held Sanaa to Aden.
His government has 32 ministers. Some are expected to move from Riyadh to Marib, east of Sanaa, a region that is also mostly controlled by loyalists.
Huthi rebels and their allies of forces loyal to former president Ali Abdullah Saleh still control vast parts of the country, including northern regions and the capital Sanaa which they overran unopposed in September 2014.
Since the coalition intervened in March 2015, more than 6,000 people have been killed in Yemen, according to the United Nations.