Jackie Baillie has been elected Scottish Labour's deputy leader after a ballot of party members.
The Dumbarton MSP replaces Lesley Laird, who lost her seat at Westminster in the general election last December.
Ms Baillie received 10,311 votes, against 7,528 for the only other remaining candidate, Glasgow councillor Matt Kerr.
The result of the UK Labour leader and deputy leader contest will be announced on Saturday.
Ms Baillie thanked party members and trade unionists for their backing - and promised to rebuild support for the party ahead of next year's Holyrood elections.
But she also acknowledged that the current focus should be on tackling the threat of the coronavirus pandemic.
She said: "When this election started, nobody expected the country to be in the grip of a global pandemic. Our collective focus will remain on the challenge that Covid-19 poses to the very fabric of our society.
"Our heartfelt thanks goes to the workers on the frontline - from doctors and nurses to social care staff, police officers and food retail workers.
"They are helping to care for us and keep us safe at a time of crisis and we should never forget their bravery and service. We will get through this together."
She continued: "It will be some time before politics returns to normal, but the next Scottish Parliament elections are now just over one year away.
"The Scottish Labour Party has a huge challenge ahead of us. Working together with Richard Leonard, our new UK leader and the entire Labour movement, I am ready for that challenge."
Ms Baillie has twice been acting leader of the party, but was sacked from the front bench team by current Scottish Labour leader Richard Leonard in 2018.
Mr Leonard insisted he was "delighted" with the result
"We will unite the party and work closely together to get the party in shape to fight the 2021 Scottish Parliament elections," he said.
"Jackie will bring a renewed energy and determination to win so I am extremely pleased that she is joining the leadership team at this critical time."