"Happy New Year to all, including to my many enemies and those who have fought me and lost so badly they just don't know what to do. Love!" the US president-elect wrote.
The message on Twitter, Trump's preferred mode of communication, caps a year in which he overcame long odds to vanquish 16 other Republicans vying to become the party's White House nominee.
He then upended Democrat Hillary Clinton in last month's general election -- her formidable political machine and bigger campaign coffers notwithstanding -- in a shock election upset.