Saint Lycerius was a 6th-century bishop of Couserans who lived during the late fifth and early sixth centuries. Born in the Iberian Peninsula, he was later associated with the region of Tarbes, where he studied under local clergy before being ordained a priest. He is historically noted for his participation in the Council of Agde in 506. During his tenure, he also managed the diocese of Tarbes while it remained vacant. He is remembered as a holy figure who is credited with performing various healing miracles.