The Toowoomba-based mining engineer was the hot favourite for Saturday's poll, which was also contested by Labor, the Liberal Democrats and Sustainable Australia.

The Groom by-election was triggered by the resignation of former minister John McVeigh, who was first elected in 2016.

At the federal election, Dr McVeigh increased the LNP margin to 20.5 per cent on a two-party preferred basis.

Mr Hamilton worked on water infrastructure projects in the Middle East and public transport in London before returning home to Queensland.

In his candidate booklet he outlined overhauling environmental laws to pave the way for major project approvals as a priority.

The father of three also wants to see industrial relations reform and tax changes to make it easier to employ young people and split income for couples raising families.

Labor's candidate was lawyer Chris Meibusch, who congratulated Mr Hamilton on his win.

"Congratulations is due, but we will hold him to account over the next 12 months as we're going to be battling a federal election in the next 12 months," he said on Saturday night.

Prime Minister Scott Morrison said he was looking forward to having Mr Hamilton's "practical problem solving experience" on his team in parliament.

"We've got a lot to work to do. See you in Canberra soon," Mr Morrison tweeted on Saturday night.

Australian Associated Press