Mr Hepburn pulled in 19,633 votes, ahead of second-placed Labour candidate Mark Griffin who received 9792. Mr Griffin will however remain at Holyrood after being elected on the Central Scotland List.
The Scottish Conservative candidate Haroum Malik received 3,375 votes and Scottish Liberal Democrat contender Elaine Ford received 678.
An elated Mr Hepburn said: "It is a great honour to have been re-elected to continue representing Cumbernauld and Kilsyth in the Scottish Parliament. It is the privilege of my life to represent the area I live in and love.
"Thank you to all 19,633 people who voted for me on Thursday. No matter how any person from Cumbernauld and Kilsyth voted my clear pledge to all those who live here is to work hard for you and to make sure the issues that matter to our communities are heard.”
A key SNP election promise was that Cumbernauld would be selected as one of the sites for so-called national elective and diagnostic treatment centres that are being established by 2025 to carry out more planned operations.
Voter turnout was 65.28 per cent, the highest of the five North Lanarkshire constituencies and up 8.6 per cent from 2016.