Adam is the son of former professional player Charlie Adam, a midfielder who played for various Scottish clubs in the 1980s and 1990s. His father died on 17 December 2012, aged 50; the cause of death was publicly revealed as suicide in 2015. Adam's mother, Eleanor, his mother, fell ill with cancer, and was a big factor in his move back to Scotland. She died in December 2020. Adam's brother, Grant, is a goalkeeper who has most recently played for Downfield. He has three other siblings: brothers Gary and Connor and sister Nicola.