Guardo is a town and municipality situated in the Montaña Palentina region in the far north of the province of Palencia, in the autonomous community of Castile and León, Spain.

According to Quirino Fernández, it could come from the Latin 'Bucca ad ardum' or 'Mouth of the Heights', which could be translated as a pass of difficult access, whereas Julio Caro Baroja links it to the Celtic word 'ward', or Land of Storms.

Guardo is first mentioned in the 10th century as 'Buardo' or 'Boardo', as a village linked to the nearby San Román de Entrepeñas Monastery in a document about property transfer.

Forming part of the Counts of Saldañas' estate, its castle, which was strategically situated on a hill above the banks of the Carrión river, was used to monitor the possible Muslim raids and to control the border with the Kingdom of León and the County of Castile.

With the onset of mining in the area at the start of the 20th century and the influx of people from other regions seeking employment in coal extraction, the character of the town underwent a radical change as the old urban centre was surrounded by new housing.

Alongside the town of Barruelo de Santullán to the northeast, Guardo became one of the main areas of conflict in the Montaña Palentina during the failed Revolution of October 1934.

After this event, as well as during the Spanish Civil War, the Nationalist uprising encountered no opposition in the region, which ensured that armed resistance to the Francoist state remained minimal in the decade following the conflict.

The municipality of Guardo, in addition to the titular town, also comprises the hamlets of Muñeca, Intorcisa and San Pedro de Cansoles.

In November 2018, 11 years after the demolition of the old town hall, Guardo's new administrative building was inaugurated and is also home to a police station and an auditorium with capacity for 400 people.