Albert Barnes Commentary 1 Kings 4:31

"For he was wiser than all men; than Ethan the Ezrahite, and Heman, and Calcol, and Darda, the sons of Mahol: and his fame was in all the nations round about." — 1 Kings 4:31 (ASV)

It is most probable that the people with whom Solomon is compared were his contemporaries, men noted for wisdom, though there is no other mention of them.

His fame was in all nations—see 1 Kings 10:1.