Luis Roberto de Lacy (11 January 1772, San Roque, Cadiz, Spain – 5 July 1817, Palma, Majorca) was a brigadier general in the Spanish Army who fought in the Peninsular War.
He came from an Irish family that had two previous generations serving in the Spanish army: his grandfather, Patrick de Lacy Sr., had been a general in the infantry regiment of the Spanish "Irish Regiment" of Ultonia, and his father, Patrick de Lacy Jr., had risen to the rank of lieutenant colonel before his early death.