Arkless was born in Stranraer in 1975.[3] He spent an early part of his childhood living in London.[3] He returned to Stranraer when he was eight years old.[3]
Arkless began to advocate Scottish independence after the 2007 Scottish Parliament election in which the SNP were elected as a minority government for the first time. After a year, he said the SNP were "doing a pretty good job". When the SNP won a majority in the 2011 Scottish Parliament election, he said in a May 2015 interview with The National, "I began to really research the figures – the GDP and tax-take – and I was completely and utterly astonished. I couldn't believe that Scotland had a higher per capita GDP, and much higher per capita tax-take over each of the last thirty-five years. I was flabbergasted and asked myself why I had believed completely the opposite all my life without every trying to make it evidence based."[5]
Arkless left his job as a solicitor to run an online business.[13] He returned to his career as a solicitor in 2020 following his departure from politics.[14]
