Thomas, named as the Sky Bet Championship Player of the Month for August - which saw him beat off competition from Fulham striker Aleksander Mitrovic, Cardiff City defender Aden Flint and QPR centre-half Rob Dickie - has now been chosen by Wales for their forthcoming World Cup qualifying fixtures with the Czech Republic and Estonia next month.
Wales head to the Czech city of Plzen on October 8 and visit the Estonian capital of Talinn three days later.
The London-born player qualifies for Wales via his mother from Newport.
Speaking about his international aspirations recently, Thomas said: "Now my challenge is to maintain this form as we head into the rest of the season, and I am determined to keep improving.
"My aim is to keep performing, keep helping Huddersfield Town get points on the board and hopefully push into the Wales squad too."
Also in the squad are Leeds United duo Tyler Roberts and Dan James, Sheffield United defender Rhys Norrington-Davies and Hull City midfielder Matt Smith.
Cardiff City's former Barnsley and Rotherham United forward Kieffer Moore, who missed last month's international training cap with Wales, is also in the squad alongside ex-Reds keeper Adam Davies and former Huddersfield loanee Danny Ward. Gareth Bale is a notable absentee through injury.