Argagnon (French pronunciation: [aʁɡaɲɔ̃]; Occitan: Arganhon) is a commune in the Pyrénées-Atlantiques department in the Nouvelle-Aquitaine region of south-western France.

Argagnon is located some 7 km south-east of Orthez and 2 km north-west of Maslacq. Access to the commune is by the D817 road from Orthez which passes through the village and continues south-east to Artix. The D275 from Maslacq to Arthez-de-Béarn passes through the eastern part of the commune. The Toulouse-Bayonne railway passes through the south of the commune parallel to the D817 but there is no station in the commune. The nearest stations are at Orthez to the north-west and Lacq to the south-east. The commune consists mostly of farmland however there are forests in the east and north of the commune.

The commune lies in the Drainage basin of the Adour and the Gave de Pau flows through the south-western edge of the commune with the Ruisseau de Clamonde flowing into it from the commune. Paul Raymond mentioned in 1863 that the Juren, a stream with its source in Arthez-de-Béarn, crossed Aragnon and flowed into the Gave de Pau

Its name in Béarnais is Arganhon. Brigitte Jobbé-Duval indicated that the name Argagnon originated from the first owner, Arcanius, and was expanded with the suffix -onem giving the meaning "Domain of Arcanius".

The following table details the origins of the commune name and other names in the commune.

Sources:

Origins:

In 1385 Argagnon and Marcerin depended on the bailiwick of Pau. Argagnon at that time had 9 fires and Marcerin had 12.