The MSP for Edinburgh Western, who was first elected to Holyrood in 2016, has painted himself as the “new hope” candidate, pledging to offer an “alternative kind of thinking” and to appeal to Scots “tired of having to choose between extremes” of nationalism.
Announcing his decision to run, Mr Cole-Hamilton said he was inspired to enter politics while working in the children’s voluntary sector and the “fire lit in me [to improve lives] rages to this day”.
Currently no other Scottish Liberal Democrat member has thrown their hat into the ring, although the ballot for nominations will remain open until August 20.
Previous leader, Mr Rennie, revealed he was standing down after ten years in the job earlier this month, after failing to lead his party to gains at the May Holyrood elections.
The Scottish Lib Dems saw their numbers fall from five MSPs to just four, reducing their status in the Scottish Parliament to that of a minor party and losing the right to quiz Nicola Sturgeon at First Minister’s Questions.
Mr Cole-Hamilton, who is his party’s health spokesman, was the MSP most likely to stand from the remaining group that includes Shetland MSP Beatrice Wishart, who was only elected for the first time two years ago, and Orkney MSP Liam McArthur, who was recently appointed deputy presiding officer of the Parliament.
A party source said Mr Cole-Hamilton was “full of energy and ideas and has the field to himself” and that a contender from within the Scottish LibDem MP group was “unlikely”.
The Edinburgh MSP came to wider Scottish prominence as his party’s representative on the parliamentary inquiry into the Scottish Government’s handling of sexual harassment allegations made against former first minister Alex Salmond.
In his leadership candidacy announcement – made in the Edinburgh Evening News – he said: “As we emerge from the pandemic, we need Scotland’s ministers and its Parliament to focus on the day job – how we get learning back on track; on how we cope with the mental health crisis and clear the backlog of cancelled operations.
"There is so much to repair, but aspiring to get back to where we were before Covid cannot be the limit of our ambitions. For many people things were terrible the way they were.
“We also can’t go back to politics as usual. For the best part of a decade, Scotland has been held back and stifled by the clash of nationalisms; the Scottish Nationalism of the SNP and the British Nationalism of Boris Johnson’s Brexiteers.
"And we are repeatedly told that the only governments available to us are to be drawn from their number. I’m sorry, but I just don’t accept that’s all there is.
“After everything we’ve been through, Scotland needs new hope, right now.
“A massive opportunity exists for an alternative kind of thinking to break through in Scottish politics. One that can capture the votes of Scots who are tired of having to choose between those extremes.
"I want to drive that alternative, so I’m putting my name forward as a candidate to be the next leader of the Scottish Liberal Democrats.”