The 36-year-old, who has had spells at Lord's in each of the last two seasons, has committed to spend two periods of the campaign in north London.
Voges will captain Middlesex in the County Championship.
Meanwhile, the club have announced Dawid Malan and James Franklin will skipper the side in the T20 Blast and One-Day Cup respectively.
They replace England limited-overs captain Eoin Morgan, who has given up the roles.
Voges, who has played 13 Tests for Australia since making his debut in June 2015, will fit his spells at Middlesex around his international commitments and the availability of Brendon McCullum, who has signed a deal to play limited-overs cricket for the club.
He will initially be available from the start of the season until early June, and is expected to return in mid-August.
"Adam's return is something we are all delighted with," managing director of cricket Angus Fraser said.
"He may not have spent a huge amount of time with us, but during the time he has been with us he has made an extremely positive impression. He continues to show what a high-quality player he is."
New Zealand batsman McCullum played his final one-day international on Monday and will join Middlesex at the conclusion of his commitments in the Indian Premier League.
The 34-year-old could potentially appear in seven T20 matches and four in the 50-over One-Day Cup.
Middlesex have re-signed Australia batsman Adam Voges as their overseas player for all formats in 2016.