Verses with the word leader in the Old Testament (3 verses):

1 Chronicles 12:27
And Jehoiada was the leader of the Aaronites, and with him were three thousand and seven hundred;

1 Chronicles 13:1
And David consulted with the captains of thousands and hundreds, and with every leader.

Isaiah 55:4
Behold, I have given him for a witness to the people, a leader and commander to the people.