Teresa Díaz II de Haro (born before 1254) was a Spanish noblewoman and a lady of Biscay, and one of five children of Diego López III de Haro, the Lord of Biscay, and Constanza de Bearne.

Her maternal grandparents were the viscount Guillermo II de Bearne and his wife, Garsenda of Provence.

Her paternal grandparents were Lope Díaz II de Haro, also Lord of Biscay, and of Urraca Alfonso de León, the illegitimate daughter of King Alfonso IX of León.

Juan Núñez was the head of the House of Lara after the death of his father Nuño González de Lara el Bueno in 1275.

Teresa had four children with Juan Núñez I de Lara: