Celeborn is an Elf of Arda, lord of Lothlórien and husband of Galadriel. Their daughter is Celebrían, who married Elrond. Their grandchildren are Elladan, Elrohir, and Arwen.
Celeborn is known to be one of the most overlooked characters in The Lord of the Rings, due primarily to being overshadowed by his awe-inspiring wife and his subsequent extremely small role in Peter Jackson's movieverse. Many fangirls, in fact, fail to recognise his existence at all, and assume Galadriel is married to Elrond. Nevertheless, he is not to be trifled with. After all, Galadriel thought enough of him to wed him.
Celeborn mistrusted Dwarves due to their theft of a Silmaril from Doriath during the First Age of Middle-earth. He and Elrond helped defend Eregion (unsuccessfully) from the armies of Sauron in the Second Age. He and Galadriel eventually became lord and lady of Lothlórien.
He briefly met the Fellowship during the War of the Ring, giving them boats for traveling down the Anduin. Long after Sauron's defeat, first Galadriel, then Celeborn left Middle-earth and returned to the Undying Lands.