Sunni Costello is Naakaii Dine’é (Mexican Clan), born for Tótsohnii (Big Water Clan). Her maternal grandfather’s clan is Tábąąhá (Water’s Edge Clan), and her paternal grandfather’s clan is Bit’ahnii (Folded Arms People). She is Navajo from Tóhajiilee, New Mexico.

Sunni serves as the Education Administrator of Indigenous Learning within the Curriculum and Instruction Division at the New Mexico Public Education Department. In this role, she partners with students, educators, and communities to ensure Indigenous voices and perspectives are woven throughout the educational experience. Shaped by her early work as a classroom educator in Navajo and Pueblo communities and later as an administrator at Santa Fe Indian School, Sunni’s work reflects a deep commitment to Indigenous education.

Throughout her career, she has centered tribal knowledge and created learning environments where Indigenous students are seen, respected, and supported. She is passionate about helping students stay connected to their identities and communities while building their own paths to success.