The Battle of Grijó (Portuguese pronunciation: [ɡɾiˈʒɔ]) (10–11 May 1809) ended in victory for the Anglo-Portuguese Army commanded by Lieutenant-General Sir Arthur Wellesley (the future 1st Duke of Wellington) over the French army commanded by Marshal Nicolas Soult during the Second French invasion of Portugal in the Peninsular War.

On 10 May British Cavalry under the command of General Sir Stapleton Cotton came into contact with outlying French Forces, after a short engagement they were scattered, both sides only suffering light casualties, but many French prisoners were taken.

[1] The following day, on the 10th, a larger force commanded by General Julien Augustin Joseph Mermet defended the forested ridge, south of Grijo.

the Anglo-allied forces under the command of Sir Arthur Wellesley (later Duke of Wellington) attacked them from the south, using a double flanking manoeuvre to threaten and drive them back.

[1] In "The History of the Rifle Brigade", Willoughby Verner describes how the ad hoc 1st Battalion of Detachments, made from soldiers and officers of multiple regiments who had become stranded with the evacuation of Coruna, fought for the first time near the village of Grijó (Vila Nova de Gaia): The Second Portuguese campaign proceeded with the Second Battle of Porto.