also: じょうおう · にょおう
Refers to a female monarch or the wife of a king. Also used figuratively for a woman who is preeminent in a field.
エリザベス女王は長く在位した。
Queen Elizabeth reigned for a long time.
彼女は社交界の女王と呼ばれている。
She is called the queen of society.
female champion
Only with reading じょおう / じょうおう
Used for a woman who has won a competition, especially in sports or games.
彼女はテニスの女王として知られている。
She is known as the queen of tennis.
She is called the queen of high society.
She defended her title as champion again this year.
She ascended the throne as queen at the age of 18.
She is called the queen of the tennis world.
女王 is a reigning queen who rules in her own right, whereas 后 is only the wife of a ruling emperor or king and holds no sovereign power.
queen of TV ratings
Historical reading; not used in modern Japanese.