Bill Spencer Jr. is a fictional character from the American CBS soap opera The Bold and the Beautiful. He is portrayed by Don Diamont. Bill Spencer Jr. is the previously unknown illegitimate son of media mogul, Bill Spencer (Jim Storm), a character that appeared from the series premiere until 1994 and then only sporadically afterwards. He is also the half-brother of Karen Spencer and the late Caroline Forrester (both played by Joanna Johnson). He was born in early March 1963.