Doreen is of Irish origin, derived from the Gaelic word "doire" meaning "from the oak grove". It was initially a surname but began to be used as a first name in the 19th century. The name gained popularity in English-speaking countries during the mid-20th century and remains somewhat popular today. Doreen is often associated with the phrase "daisy roots" due to its similarity in pronunciation to the flower's common name, although there is no direct etymological connection between the two.
"Doreen's popularity as a baby girl name appears to have two peaks - one in the late 50s and another in the mid-60s."