That made the 48-year-old, who joined the Basque club in December, the first American head coach to win a major trophy in one of Europe's top five leagues. The win over Atletico Madrid also secured the club a place in next season's Europa League.
Matarazzo took charge with Sociedad near the LaLiga relegation zone, and he guided them to a 10th-place finish on 46 points.
"I connected very well with the people of Gipuzkoa, with the players, with the people at the club. I share similar values with them, which makes it easier to connect," Matarazzo said in a statement.
Sociedad begin their 2026/27 La Liga campaign away to Real Madrid on August 17th at the Santiago Bernabeu.