Regino Sáinz de la Maza y Ruiz (7 September 1896 – 26 November 1981) was a Spanish classical guitarist and composer.
Sáinz de la Maza was born in Burgos. At ten, he got his first guitar and started his musical studies with Santiago Landache (solfege), José Nicolás Quesada (piano), and Eugenio Rodríguez Pascual (guitar). In 1910, his family moved to San Sebastián, where he studied piano with Germán Cendoya, harmony with Beltrán Pagola and guitar with Luis Soria. A year later, he moved to Bilbao, where he continued his studies with Hilarión Leloup. At 18, he performed at his first concert at the Teatro Arriaga of Bilbao.
He later moved to Barcelona, where he worked as a concert musician. There, he befriended Miguel Llobet and Andrés Segovia. In 1920, he played for the first time in Madrid. A year later he toured South America, giving 90 concerts. On 20 May 1920, he was awarded a Golden Medal by the National University of Buenos Aires, where he became friends with composer Antonio José Martínez Palacios, who dedicated some guitar compositions to Sáinz de la Maza.
He toured Europe, giving concerts in France in 1926, in Germany in 1927 and Great Britain in 1928. Five years later he toured South America for the second time, with concerts in Uruguay, Argentina, and Brazil.