King Wu of Zhou (died c. 1043 BC), personal name Ji Fa, was the founding king of the Chinese Zhou dynasty. The chronology of his reign is disputed but is generally thought to have begun around 1046 BC and ended with his death three years later.
King Wu was the second son of the Zhou elder Ji Chang (posthumously titled King Wen) and Tai Si. In most accounts, his older brother Bo Yikao was said to have predeceased his father, typically at the hands of King Zhou of Shang, the last king of the Shang dynasty. In the Book of Rites, however, it is assumed that his inheritance represented an older tradition among the Zhou of passing over the eldest son. (Fa's grandfather Jili had likewise inherited Zhou despite having two older brothers.)