The given name Lynsey is derived from the Old English name Linuseye, which can be traced back to the 7th century AD. Linuseye is believed to be composed of the Old English elements "lin" meaning flax or linen, and "seye" meaning small island or dry ground. This suggests that the name may have originally referred to someone who lived or worked near a flax field on an island or raised ground.

The earliest recorded use of the name Lynsey is found in the Domesday Book of 1086, a comprehensive survey of landowners and estates commissioned by William the Conqueror. It lists a landowner named Linuseye in the county of Norfolk, England. Over the centuries, variations in spelling emerged, including Linsey, Linsie, and Lyndsay.

In medieval times, the name Lynsey gained associations with the Scottish clan Lindsay, whose ancestral lands were in the county of East Lothian, Scotland. The Lindsay family claimed descent from a 12th-century Anglo-Norman nobleman named Walter de Lindesay, whose name is believed to be a variant of the Old English Linuseye.

One notable historical figure with the name Lynsey was Lynsey de Aubigny, a 13th-century noblewoman and heiress who became Countess of Arundel through her marriage to John FitzAlan, 7th Earl of Arundel. She played a role in the Second Barons' War against King Henry III.

Another individual with the name Lynsey was Lynsey de Guernevale, a 14th-century landowner and knight in the service of King Edward III of England. He participated in the Hundred Years' War against France and was present at the Battle of Crécy in 1346.

In the 16th century, Lynsey Percevall was a notable female writer and translator who produced English versions of several works by French authors, including The Hundred Tales of Tragical Sayings by François de Belleforest.

During the 17th century, Lynsey Howard was a English Puritan minister and author who wrote extensively on religious subjects and advocated for the reformation of the Church of England.

In more recent times, one of the most famous individuals with the name Lynsey was the 20th-century American actress Lynsey Wagner, known for her roles in films such as The Paper Chase and The Midnight Man. She was born in 1949 and is still active in the entertainment industry.