Marcos Sergio Bautista Manuel de Lezama Leguizamón Sagarminaga (1862–1924) was a Spanish entrepreneur and politician who developed the family-owned mining conglomerate that controlled iron ore, carbon, fluorite, anhydrite and plaster mines in Vascongadas and Asturias, and politically supported the Traditionalist cause. In the 1910s he led the Carlist provincial organisation in Biscay but in 1919 he joined the breakaway Mellistas. His political career climaxed in 1921–1923, when he served two terms in the Senate. In 1907–1911 he held a seat in the Biscay self-government Diputación Provincial, and in 1893–1897 he was member of Bilbao town hall.