He attended West Calder High School and has lived in the Dunfermline area since 1990, serving as a councillor for Rosyth and North Queensferry ward on Fife Council for nine years before becoming an MP.

Chapman has repeatedly urged Scotland's transport ministers to reopen the line, citing the benefits it could bring to communities in West Fife and further afield.

Following the first coronavirus lockdown in June 2020, he wrote an article highlighting the Scottish Government's efforts to foster relations with its Nordic neighbours, which said: "Now that the world has been turned upside down by the horror of this pandemic, connections with these smaller northern nations seem all the more important in terms of what we can learn from their individual responses to the crisis.

In an article for the National, he also said:  "There’s never been a more important time for Scotland and the UK to cement our alliances with these Councils as we grapple with the major challenges of the COVID-19 pandemic, Brexit and the enormity of the climate crisis.

"[20] In August 2019, as the SNP's Spokesperson on Defence Procurement, Peace & Nuclear Disarmament, Chapman claimed without presenting any evidence, that the British Army's 77th Brigade was involved in "attacking and undermining [the] democratic choices" of the Scottish people.