Christian V, Count of Oldenburg ( – 1399) was the ruling count of Oldenburg from 1368 until 1398. He was born sometime before 1347 to Count Conrad I of Oldenburg and Ingeborg of Brunswick. After his father died in 1347, he ruled Oldenburg jointly with his elder brother . In 1403, his son became joint ruler with his other son Dietrich, Count of Oldenburg, and with the son of , , who had previously ruled by himself from his father's death in 1401.
He married Agnes of Honstein, and the Danish Royal houses of Oldenburg and Schleswig-Holstein-Sonderburg-Glücksburg descend from him via his son and successor Dietrich, Count of Oldenburg. Through the dynastic marriages of his descendants, he is an ancestor of many European Royal houses.