Scottish Labour announces its selection of the Westminster MP to succeed Johann Lamont, after her shock departure in October.
Mr Murphy said it was a “remarkable honour” to be chosen as Labour’s new leader in Scotland, after picking up 55.7 per cent of the party vote.
The leadership contest was triggered when Johann Lamont stood down suddenly in October after accusing Westminster colleagues of treating Scotland like a “branch office”.
His nearest rival in the contest, Holyrood health spokesman Neil Findlay, secured 34.99 per cent of the vote, while former Scottish Executive minister Sarah Boyack came in with 9.24 per cent in third place.
A minority are falling behind, denied opportunity, trapped Jim Murphy
Kezia Dugdale, MP for the Lothian region, has been elected as the party’s deputy leader.
Mr Murphy, MP for East Renfrewshire, said his election was “a fresh start for Scottish Labour”.
Read: Can Jim Murphy save Scottish Labour?
“Scotland is changing and so too must Scottish Labour,” he added. “I’m ambitious for our party because I’m ambitious for our country.”
Announcing his leadership bid in November, Mr Murphy said his party should “apologise” for not listening to voters after electoral defeat.
The shadow international development secretary said: “I want to apologise because twice Scots have said they didn’t think we were good enough to govern in Scotland – in 2007 and 2011. We didn’t listen to them. That has to change.”
Mr Murphy played a key role for the better together campaign during the Scottish Independence referendum when he carried out his pro-union 100 Streets in 100 Days tour.
Accepting his new role as leader, he said there was need to “unite” Scotland, calling it “one country but two nations” – divided not between people for or against independence, but between society’s haves and have-nots.
I will always put Scotland first Jim Murphy
“The majority are fulfilled, getting on, getting by, being successful,” he said.
“A minority are falling behind, denied opportunity, trapped, unable to escape the hardship of their upbringing.
“That inequality is wrong and it is my driving purpose, it is our driving purpose, it is the Scottish Labour Party’s driving purpose to end that type of inequality once and for all.”
Read: New powers for Scotland - but can they save Labour at the polls?
Mr Murphy said the best way to tackle poverty was to boost the economy, adding: “The debate about how we spend our wealth starts with how we earn it.”
He called on Scots to work together “regardless of politics and regardless of referendum” and work together to “build the fairest nation on earth”.
He added: “I was born here, I live here, I will lead here. I will always put Scotland first.”