Esau is the clearest answer
Genesis introduces Esau, Isaac and Rebekah's firstborn son, with a striking physical description. He came into the world red in appearance and covered with hair. The passage says this was why he received the name Esau (Genesis 25:25).
So, if by red hair you mean someone whose appearance was explicitly linked with redness and hair, Esau is the closest and clearest answer in Scripture. The Bible does not give a modern colour label such as "ginger" or describe the exact shade of his hair. Still, the combination of red colouring and abundant hair is hard to miss.
And the first came out red, all over like an hairy garment; and they called his name Esau.
Why was Esau called Edom?
Esau was also called Edom, a name connected with red. Later, exhausted and hungry, he asked Jacob for the red stew Jacob had prepared. The account links that moment with the name Edom (Genesis 25:30).
That detail doesn't prove the colour of Esau's hair by itself. But alongside his birth description, it strengthens the picture of a man repeatedly associated with redness. His story goes on to show the cost of trading his birthright for immediate relief, a choice Hebrews later recalls as a warning about treating holy things lightly (Hebrews 12:16).
What about David?
David is sometimes suggested as another red-haired person because Samuel describes him as ruddy when he is brought in from tending sheep (1 Samuel 16:12). When David faces Goliath, the same description appears again (1 Samuel 17:42).
Yet "ruddy" does not necessarily mean red-haired. It can point to a reddish or healthy-looking complexion. The Hebrew word behind it, admoni, is related to redness, but the verses do not specifically say that David's hair was red. It is fair to say David had a ruddy appearance, while Esau remains the stronger answer to the question about red hair.
And he sent, and brought him in. Now he was ruddy, and withal of a beautiful countenance, and goodly to look to. And the Lord said, Arise, anoint him: for this is he.
A small detail with a real story
The Bible rarely focuses on hair colour simply as a curiosity. Esau's appearance helps distinguish two very different brothers from the beginning, while David's youthful, ruddy appearance contrasts with the kind of king people expected. God tells Samuel not to judge by outward appearance, because he sees the heart (1 Samuel 16:7).
That makes these descriptions worth noticing, but not over-reading. Esau is the Bible's best-supported example of someone associated with red hair. David may have been red-haired, but Scripture leaves that uncertain. Reading the surrounding stories gives the details their proper place.