Finch tallied 11 votes in the 12-month voting period, which started on January 8 last year and does not include the current Gillette T20 Tri-Series against England and New Zealand.
In a year that saw the Australians play just five games, three of them without some of their best players due to a scheduling clash with the Test tour of India, Finch earned one vote more than Zampa and Henriques.
And the fact that Finch is the only player in the top-five vote-getters to currently be in Australia's best T20 XI underlines the difficulties selectors have had in trying to improve their historically poor record in 20-over cricket.
The voting period took in the three-match series against Sri Lanka last February, which Australia lost 1-2, and the two matches in India last October that were shared.
Zampa's tally of 10 votes came despite being controversially left out for one of the three Sri Lankan matches, to which he responded with a man-of-the-match performance of 3-25 in the third game in Adelaide.
And while he missed out on the top award, the fact he accrued more votes from his teammates (seven) than any other player would be of some comfort even though the combined votes from players, media and umpires saw Finch win the award overall
The right-hander, who also won the award in 2014, scored 158 runs in the voting period to edge out Henriques (145 runs), who was left out of the squad for the current tri-series after a KFC BBL campaign that included some time away from the game for personal reasons.
Finch posted scores of 43, 12, 53, 42 and 8 in five matches, all of them as an opener, and his position in Australia's batting line-up will be an intriguing sub-plot ahead of their departure to New Zealand on Tuesday for the conclusion of the tri-series.
And after three wins in a row, this current campaign is the best sign in recent years that Australia's T20 fortunes are on the improve ahead of the next ICC World T20 on home soil in 2020.
T20I Player Of The Year - Voting:
Aaron Finch - 11 votes
Adam Zampa - 10 votes
Moises Henriques - 10 votes
Jason Behrendorff - 7 votes
Michael Klinger - 5 votes