Also used as a Spanish name with mainly feminine usage, but also rare masculine usage. It was first given as a masculine name in Mexico in the mid 17th century and in the mid 18th century as a feminine name with usage increasing across the Spanish-speaking countries in the 19th and 20th centuries. [noted -ed] Though, overall, it's an uncommon name in Spain right now, it was most popular in the 1980s and 1990s.In Portugal, it is approved as feminine second-element name (added onto names such as Maria -> Maria do Loreto).
I love this name so much! I see it more as a boys name, but I went to an all-girl school called "Loretto," so I can see it as unisex. But I like the double "T" in the name.
Sources: https://forebears.io/forenames/loreto
https://www.ancestry.com/name-origin?surname=Loreto