Thornton is a small village in Pembrokeshire, Wales. It is located approximately 1 mile outside of Milford Haven belonging to the Tiers Cross community. It is mainly residential in nature. Until recently it was contained within the parish of Steynton.

The Iron Age fort, Thornton Rath, was a defensive enclosure, whose remains can still be seen. It sits on a promontory, above two valleys, and ditches and banks are all that remains. The earthwork measures 88m by 58m.

There is a Grade II listed building in the village, now called Sunnybank, once a part of Thornton House, and possibly the coachman's house, dating from about 1800.

The cemetery for Milford Haven and Steynton parish is in Thornton. There is a large number of military graves, including those of men who lost their lives in landing craft that foundered off the Welsh coast.

Thornton Baptist Chapel was built in 1867 in simple round-headed style, and housed a British School in its lower level. Records are held by Pembrokeshire County Council.