This article discusses whether the metaphor of "king" can still be used in Christian God-talk. Firstly, it is argued that the "king" metaphor for God is an indispensable key metaphor in both the Old and the New Testament. "King" has become a root metaphor in the canonical text of the Old Testament and Jesus' proclamation of the coming kingdom of God presupposes that God is king. Secondly, the Biblical meanings of the metaphor are explored. God's kingship implies his authority and power to fight the forces of evil, to liberate and lead his people and to control the events of history. Modified by Jesus Christ, God's kingship is universal, non-violent and in accordance with his love. Then, the use of the metaphor in contemporary God-talk is considered. Because "king" is the only metaphor that can give expression to God's ultimate highness and authority, it cannot be replaced by others. In the concluding section the "king" metaphor for God is conceptually explained in terms of the relationship, the agency and the power of God it implies.