P.D.Q. Bach.
Serial killer Ted Bundy. Another person who thought his mother was his sister. There’s some speculation that his mother’s father was also his father, but his mother denies it.
Interesting, the websites are divided on whether or not Vernon Winfrey ever married Vernita Lee. Nonetheless, Oprah would make this list in her own right, as she gave birth to a daughter in her early teens (I can’t recall whether the baby was stillborn or died soon after birth) - the circumstances regarding the baby’s conception were the subject of one of her programmes a few years ago.
Minor point of clarification - Maria Montessori was born to married parents. It was her son, Mario, who was illegitimate - the result of an affair with a married colleague. Maria M never married.
I don’t think that Ingrid Bergman and Roberto Roselini were married when Isabella Roselini was born, but I could be mistaken.
What? No one’s mentioned Marilyn Monroe yet?
Also, actress Mariska Hargitay, daughter of Jayne Mansfield and, supposedly, Mickey Hargitay. She’s admitted her biological father is Italian singer and producer Nelson Sardelli, but she doesn’t like to publicize it, as she is so close to Mickey—one reason I’ll not be able to do a book on Jaynie, dammit.
Robert Burns had an illegitimate daughter. He fought to get custody of her, and she was raised by his mother. He wrote a poem called A Poet’s Welcome to his Love-Begotten Daughter on her birth:
Welcome, my bonie, sweet, wee dochter!
Tho’ ye come here a wee unsought for,
And tho’ your comin I hae fought for
Baith kirk and queir;
Yet, by my faith, ye’re no unwrought for —
That I shall swear!