Scottish Labour named Anas Sarwar as their new leader on Saturday, ahead of an election for the country's devolved parliament in May.
Sarwar, a Glasgow member of the Scottish parliament (MSP), succeeds Richard Leonard who resigned in January.
Labour's fortunes have flagged in Scotland with the Scottish National Party (SNP) the dominant force. Labour has 23 out of 129 seats in the parliament.
"I want to say directly to the people of Scotland - I know Labour has a lot of work to do to win back your trust because if we're brutally honest you haven't had the Scottish Labour party you deserve," said Sarwar.
"With rising injustice, inequality and division, I'm sorry we haven't been good enough.
"And I will work day and night to change that, so we can build the country we all need."
Sarwar received 57 per cent of the vote, overcoming Monica Lennon, who got 42.4 per cent.
He becomes the the first non-white and also first Muslim leader of a major political party in the UK.
"That doesn't say something about me. That says something great about Scotland and its people," Sarwar said.
He follows in the footsteps of his father Mohammed, who was the first Muslim MP after being elected to Glasgow Central in 1997.
SNP leader Nicola Sturgeon took to Twitter to congratulate Sarwar, saying: "He (and his dad before him) and I are long-time political opponents, but I also like and rate him. That may not always be obvious in the weeks ahead as election battle is joined, so worth saying so now."
Sturgeon wants a strong showing for her party in the election on May 6 to hand her a mandate to hold a second referendum on independence - something British prime minister Boris Johnson has said he will not approve.
Opinion polls indicate a majority back a second referendum.
But the SNP is in the midst of a bitter row between Sturgeon and her predecessor Alex Salmond that could eventually put pressure on her to resign and threatens to damage the independence movement.
Leonard said in January it was in the best interests of the party for him to stand down before the May election.
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During the hearing, Clifford denied all the charges except for the rape charge, which was added to the indictment at the session. (Photo: Hertfordshire Police /Handout via REUTERS)
Man pleads not guilty to murder of BBC presenter's family
A 26-year-old man has pleaded not guilty to charges of murdering the wife and two daughters of BBC sports commentator John Hunt in a crossbow and knife attack.
Kyle Clifford, who also faces charges of rape, appeared via video link at Cambridge Crown Court on Thursday.
Clifford, arrested in July after a manhunt, is charged with three counts of murder, one count each of rape and false imprisonment, and two counts of possessing offensive weapons – a 10-inch knife and a crossbow.
During the hearing, Clifford denied all the charges except for the rape charge, which was added to the indictment at the session.
He is expected to enter a plea for that charge at a later date.
The victims were Carol Hunt, 61, wife of horseracing commentator John Hunt, and their daughters Louise, 25, and Hannah, 28.
An earlier hearing revealed that Louise had been found tied up and that both she and her sister had been shot with a crossbow, while their mother had been stabbed with a knife.
The fatal attack occurred at the family’s home in Bushey, a commuter town near Watford, northwest of London.
(With inputs from AFP)