Comillas is a historic municipality situated in the northern region of Cantabria, Spain. The town is historically significant due to the Marquessate of Comillas, a noble fiefdom that maintained its seat of power within a local castle overlooking the area.
The town is well-regarded for its architectural heritage, which includes a variety of medieval and baroque buildings. It also formerly hosted the Comillas Pontifical University, the old campus of which remains one of the most prominent architectural landmarks in the municipality.