Thomson made her international debut against England at
Broadwood in the 2016 Six Nations opener. She is a Scottish Rugby-supported player, who was the captain for Scotland Women for the 2018/19 season. When Scotland beat Italy in the Women's Six Nations Championship of 2017, Thomson played a key role, setting up the home side's first try for Chloe Rollie, helping the team fight back from 12–0 down to secure a 14–12 victory. Thomson was selected to travel to South Africa with Scotland Women in their first ever tour and their first ever matches in the Southern Hemisphere in 2019, where they obtained two victories. She is vice-captain for the 2021 Women's Six Nations Championship. The team lost to England and Italy, before beating Wales 27–20 to claim fifth place in the championship. Scotland captain of the 2021 Women's Six Nations,
Rachel Malcolm, said of her teammate, “For me Lisa is probably the most well-rounded rugby player we have in our Scotland team. She leads so well in terms of organising the game and she has a brilliant rugby head and an unbelievable skillset." She turned professional in 2016, when she was enlisted as a Stage Three player in the BT Sport
Scottish Rugby Academy. In 2022, she was captain at the
2021 Women's Rugby World Cup. and
2022 Commonwealth Games. In June 2024, she was named in the British squad for the
2024 Paris Olympics. The team finished seventh. She was named in
Scotland's squad for the
2025 Six Nations Championship. She was also selected in the Scottish side for the
Women's Rugby World Cup. == Personal life ==