Sales of vegan dishes at Greene King sites increased by 265% year-on-year in 2019, according to the pub giant.
The first weeks of 2020 have seen a further increase in sales of vegan main courses of 14% compared to the previous year, which the group attributes to more consumers participating in Veganuary.
Greene King increased the number of vegan dishes it offers by 45% across its branded venues, which include Farmhouse Inns, Chef & Brewer, Hungry Horse and its locals pubs, in the last 12 months.
Chief commercial officer Phil Thomas said: "It's no secret that across the sector we're seeing an increase in demand for vegan dishes as more and more customers choose plant-based meals, but I think what is surprising is the rate of growth.
"I think there was a longstanding assumption that vegan food was generally unexciting, but because of the creativity and passion we're putting into developing our plant-based dishes, we're increasingly seeing traditional meat-eaters actually choosing a vegan option when dining out on the strength of the dish itself."
Greene King will roll out a new vegan pizza across 250 Hungry Horse pubs in February and expects it plant-based food sales to jump again in 2020.