Itsuo is a unisex given name of Japanese origin, derived from the elements "itsu" meaning "one" and "o", which denotes honorific title or respectful prefix. Itsuo gained popularity in Japan during the mid-20th century, particularly among parents who wished to give their children unique names with meaningful interpretations. The name has been used for both boys and girls, although it is more commonly associated with males.
"The name Itsuo had a consistent popularity between 1922 and 1924 with around 7 to 10 births per year, but then dropped to 6 births in 1932. Overall, there were 30 births with this name across these years."