Sofia is famed for its Shkembe Chorba, a traditional Bulgarian soup made with beef tripe, paprika and milk usually served with a garlic sauce. Per capita consumption of tripe there is one of the highest of any European conurbation, apart from Florence and Wigan.
Speaking after the city was named, TMB chairman Sir Norman Wrassle said: "We'll be delighted to join our colleagues from offal marketing agencies all across Europe next October to celebrate what is only the 5th ever World Tripe Day."
Sir Norman said he looked forward to the day being marked all across the globe. The announcement came as the TMB confirmed its programme of fact finding visits for the next 12 months.
"After the launch of Forgotten Yorkshire in Ossett on Sunday 3 December, we'll be making preparations for a hectic schedule that takes in Lisbon, Valencia and Sardinia. Tripe is truly going global, and 2018 looks set to be the Year of Tripe," Sir Norman said.