This case report describes a 10‐year‐old, male, neutered, indoor–outdoor, domestic shorthair cat presented for hyporexia and dysphagia of 1‐month duration tentatively attributed to a recent diet modification. The cat was ultimately referred for a second opinion. Examination under sedation confirmed a small, soft, fluctuating mass in the ventral intermandibular space. A fine‐needle aspirate of the mass revealed its contents to be of the salivary gland origin. The sublingual–mandibular salivary gland on the left side was surgically resected, and the left sublingual mucocele (ranula) was marsupialised. Histopathology confirmed a sublingual sialocele of the resected gland. The cat recovered completely, and there has been no recurrence with an 18‐month follow‐up. A sublingual sialocoele is uncommonly seen in cats, but it should be on the differential diagnosis list for dysphagia in cats, especially when a sublingual mass is present.