Recorded in several forms including Warfield and Warfeild, this is an English surname. It is locational from the village of Warfield in Berkshire, or possibly from Warfield Street, in Wokingham, Surrey. It seems very unlikely that the name has anything to do with 'war', it almost certainly derives from the pre 7th century Olde English word 'waernan' meaning the wren bird, and hence a field which was particulary full of such birds. Another possibility is a derivation from the ancient word 'wer', used to describe a dam or weir, one probably used for fish farming, and found in such place names as Warford. The village of Warfield in Berkshire is first recorded as Warwelt in the Domesday Book of 1086, and again as Warefeld in the pipe rolls of the county in 1171. Locational surnames by their nature are usually 'from' names. That is to say names given either to the local lord of the manor and his descendants, or more usually to former inhabitants who for whatever reason, left their original homes, and moved elsewhere. In so doing they took, or were given, as their surname, the name of their former village. It is unclear as to when the surname was first recorded, but Roger Warfilld as spelt, appears in the surviving registers of the church of St Stephen Wallbrook, in the city of London, on May 28th 1562 [when he brought his son John for christening]. © Copyright: Name Origin Research www.surnamedb.com 1980 - 2016
Warfields were particularly prominent in early Maryland history - see "The Founders of Anne Arundel and Howard Counties", by Joshua Dorsey Warfield https://archive.org/stream/foundersofannear00warf/foundersofannear00warf_djvu.txt
and "Anne Arundel Gentry", by Harry Wright Newman (available online only through a very tricky link at Familysearch.org - try your local library or LDS Family History Center).