From Old French 'l'isle' meaning the island; a surname turned given name.
Lyle began as an English surname before it settled into life as a given name. Its root is Norman French, from l'isle, meaning "the island," so the name originally marked someone who lived on or near an island or came from a place so called. That journey from landscape word to family name to first name is a very British one, and it gives Lyle a crisp, old-world neatness.
The sound is compact and modern to contemporary ears, but the structure underneath it is medieval and geographic. As a personal name, Lyle gained particular visibility in the English-speaking world in the late nineteenth and early twentieth centuries, when surname-style boys' names became fashionable. It has been carried by figures such as singer-songwriter Lyle Lovett, whose dry wit and Texan distinctiveness have helped color the name with artistic intelligence.
Lyle also appears in fiction and popular culture often enough to feel familiar without being commonplace. Its image has shifted over time: once sturdily masculine and patrician, later a little mid-century, and now somewhat revived as a lean, understated classic. That "island" origin also gives it a pleasing symbolic undertone, suggesting independence, self-possession, and a certain quiet separateness.