Loinaz Jauregi Bereziartu is a Spanish actress known for her work in both live-action productions and voice dubbing. She was born on January 8, 1962, in Beasain, in the province of Gipuzkoa, within the Basque Country, Spain. Her professional career includes credits as an actress, producer, and casting director.

In the field of voice acting, Jauregi is recognized for dubbing anime and animated characters into the Basque language, Euskara. Her most prominent anime voice role is Ume Matsuzaka in the Basque-language version of the long-running series Shin Chan. Ume Matsuzaka is the kindergarten teacher of the main character, Shinnosuke Nohara. Beyond the studio recording for the series, Jauregi has also demonstrated her voice work for the character in public. In 2012, she participated in a live dubbing workshop at the Durangoko Azoka, a cultural fair in the Basque Country, where she performed as Matsuzaka in a direct dubbing demonstration for an audience.

In addition to her work in animation, Jauregi's acting career includes on-screen roles. She is known for appearing in Spanish television series such as Periodistas (1998) and for her work in short films including Haiku, 1975 (2016) and Fuego (2014).