Abstract Oral focal mucinosis is an uncommon disorder primarily reported in people and characterised by excessive hyaluronic acid production in the mucosa. This report describes a novel occurrence of oral focal mucinosis in a 3‐year‐old French Mastiff with brachycephalic obstructive airway syndrome, presenting with severe respiratory distress and mucin deposits in the oral cavity, specifically the soft palate and the epiglottis ventral aspect. This is the first account of oral focal mucinosis at these sites and its association with brachycephalic obstructive airway syndrome in veterinary literature. Patient stabilisation followed by folded flap palatoplasty and mass excision resulted in significant clinical improvement. The presence of mucin on histopathological analysis confirmed the diagnosis of oral focal mucinosis. This case presents new clinical manifestations and anatomical sites not previously reported in oral focal mucinosis. It also raises questions as to whether trauma or chronic inflammation may influence cases of oral focal mucinosis in dogs.