Theresa is of uncertain origin; it is usually linked to the Greek theros, "summer", or therizein, "to harvest", and first appears in Spain in late antiquity. St. Teresa of Ávila, St. Thérèse of Lisieux and Mother Teresa of Calcutta made it one of the great Catholic names. Theresa was a top 100 name in the US from the 1930s to the 1970s; it stood at number 418 in 2000 and has since slipped to number 1559 in 2025.