The success at the 20th World Scotch Pie Championships also saw the firm win a silver award for its popular sausage rolls.
Meanwhile Richards Family Butchers of Grangemouth were handed a silver award for their Scotch Pie - narrowly missing the world title - and also won a bronze award for their steak pie.
A spokesman for Thomas Johnston said: “We are delighted with our win and can go away with our heads held very high indeed.
“To have been judged as one of the best in land against so many of our peers is a huge achievement.”
The local winners received the awards from TV personality and entrepreneur Carol Smillie at a ceremony in Cumbernauld.
More than 80 butchers and bakers entered over 450 pies, sausage rolls, bridies, savouries and apple pies in the competition, 200 hopefuls attending the awards event.
Head judge Ian Nelson said: “The competition aims to highlight that bakers and butchers create high quality pastry products. “Recognising the ‘great and the good’ in this way rewards excellence and raises the bar in the industry.”
Ronnie Miles, President of Scottish Bakers, said “Once again we have brought together the best pies and baked goods in the land and we can really celebrate the achievement of our hard working butchers and bakers.
“My heartfelt congratulations go everyone taking away a prize - they are all winners in my book.”