The former party leader's victory came as the SNP won all six seats in the north east of Scotland.
Callum McCaig won Aberdeen South from Labour, and Kirsty Blackman did likewise in Aberdeen North.
Stuart Donaldson won West Aberdeenshire and Kincardine, Angus Robertson held Moray, and Eilidh Whiteford was re-elected in Banff and Buchan.
However, Alistair Carmichael retained Orkney and Shetland for the Liberal Democrats.
Mr Salmond, speaking after defeating the Liberal Democrats in Gordon, said: "The Scottish lion has roared this morning across the country.
"There is a swing under way in Scotland the like of which has not been seen in recorded politics.
"I look forward to representing every constituent, regardless of their political views."
Mr Salmond claimed a 47.7% share of the vote, over Christine Jardine on 32.7%, as the SNP saw a 25.5% increase.
Mr McCaig's win, with a 29.8% increase, saw Anne Begg lose her seat. He said he was "honoured and thrilled".
Ms Blackman's win was on the back of a 34.2% increase to defeat Richard Baker.
Mr Donaldson's West Aberdeenshire and Kincardine victory came after a 25.9% share increase. Lib Dem Sir Robert Smith, who lost the seat, was pushed into third behind Conservative Alexander Burnett after a 17% fall.
Mr Robertson increased his majority for a 49.5% share, as did Ms Whiteford, with a 19% vote increase and a 60.25% share.
Mr Carmichael's victory came after a 20.6% fall in his share of the vote.
He thanked the people of Orkney and Shetland for giving him the "tremendous privilege" of serving them again.
Alex Salmond said the Scottish lion had "roared", after he won the Gordon seat for the SNP in the general election.