After attending Madras College, a state school in St Andrews,[6] he graduated from the University of Aberdeen with a degree in politics and international relations.

There, he was President of the Students' Representative Council from 1999 until 2000, where he was actively involved in negotiations with coalition ministers to abolish tuition fees in Scotland.

[10] Following the 2015 general election, Deputy Prime Minister and Liberal Democrat Leader Nick Clegg quoted Cole-Hamilton when delivering his resignation speech.

[14] In 2018, Cole-Hamilton successfully persuaded the Scottish Government to reverse a planned funding cut to HIV Scotland that would have sunk that organisation.

[15] In 2020, during parliamentary deliberation of the first Coronavirus Act, Cole-Hamilton introduced amendments which forced a government U-turn on their proposals to abolish jury trials in Scotland for the duration of the emergency.

[17] In February 2021, Cole-Hamilton was forced to apologise after having been seen swearing at Minister for Children and Young People Maree Todd during an online committee hearing.

[18] He wrote Todd a letter of apology, as well as publicly apologising in the Holyrood Chamber the week after, saying his language was “neither parliamentary nor respectful.”[19] The National reported in February 2024 that revisions to Cole-Hamilton’s Wikipedia article relating to the incident were ‘removed’ via a computer in the Scottish Parliament.

[21] On 27 July 2021, Cole-Hamilton announced his intention to stand in the upcoming Scottish Liberal Democrats leadership election to replace Willie Rennie.

[24] He has prioritised campaigning on children's mental health, long covid, tackling the climate crisis and supporting Ukrainian refugees.

[29] After Rishi Sunak called a general election on 22 May, Cole-Hamilton began campaigning for the Lib Dems, looking to “tear down the acid yellow wall of the SNP”.

[34] On 17 June, Cole-Hamilton unveiled the Scottish Lib Dems manifesto, which called for more funding for local agriculture, a new minimum wage for care workers, and more support to mental health services, among other issues.

[39] The party won 6 seats in Scotland, gaining two in Inverness, Skye and West Ross-shire and Mid Dunbartonshire from the SNP.