The company, whose parent company is Greene King, owns around 70 pubs across Scotland. "For our fish and chips to be recognised in this way is a great achievement, especially as it is the first year that Belhaven has entered the competition," said catering operations manager George Kay.
"We knew the dish was special, because not only is it made with fresh Scottish haddock but it is our best-selling item on the menu across Scotland.
"We pride ourselves on offering our customers excellent value, service and quality, and to now be able to officially call our fish and chips award winning is fantastic."
Greene King brand Olde English Inns received the accolade in 2012 and Hungry Horse was also a finalist this year.
The awards ceremony was organised by the seafood authority, Seafish and was hosted by celebrity chef Jean-Christophe Novelli, at the London Lancaster hotel.