David Davis (February 14, 1745 – July 3, 1827, known as "Castellhywel" or "Dafis Castellhywel" to differentiate him from others of the same name, was a Welsh minister and poet.
He was born at Llangybi in Cardiganshire and educated at Carmarthen Academy. He became a minister at Ciliau Aeron, where he married the local squire's daughter. In about 1782 he moved to Castellhywel in the Cletwr valley, where he opened a school.
