Torrelavega (Cantabrian: Torlavega) is a municipality and important industrial and commercial hub in the single province Autonomous Community of Cantabria in northern Spain.

It is situated roughly 8 kilometres from the Cantabrian Coast and 27.5 kilometres from the capital of the Autonomous Community, Santander, half way between the Principality of Asturias and the Basque Country. The rivers Saja and Besaya flow through the city.

It is the capital of the comarca of Valle del Besaya which includes also composed of the municipalities of Suances, Polanco, Cartes, Los Corrales de Buelna, Cieza, Arenas de Iguña, Bárcena de Pie de Concha, Molledo, Anievas and San Felices de Buelna.

Its highest point is 606 metres and its lowest point is 12 metres.

Torrelavega is a regional center for industry and transport, and its weekly livestock fair is famous in Spain. Its stadium is known as El Malecon. The Cave of Altamira, famed for the prehistoric paintings found inside, is about 10 kilometers northwest of the city.