Welwyn Garden City is a town (not a city) in Hertfordshire, England. Welwyn Garden City is also known as WGC or, somewhat incorrectly, Welwyn, although this can cause confusion with the village called Welwyn which lies a few miles to the northwest of WGC.

Arms of the former Welwyn Garden City Urban District Council

Welwyn Garden City, as its name suggests, is a "garden city", founded by Sir Ebenezer Howard in the 1920s following his previous experiments in Hampstead Garden Suburb and Letchworth Garden City. Howard had called for the creation of new towns of limited size, planned in advance, and surrounded by a permanent belt of agricultural land, as a role model for lower-density suburban development. Howard believed that such Garden Cities were the perfect blend of city and nature.

The BBC TV series Superstars was famously filmed in Welwyn Garden City throughout the 1970s and 1980s.

Famous Welwyn Garden City former and current residents include The Subways, David James (England goalkeeper), Artist Damien Hirst, Nick Faldo (golfer), Lisa Snowdon (model) and Rolling Stones' Mick Taylor.

Welwyn Garden City is well known by avid readers of the side of breakfast cereal boxes in Britain as the town where Shredded Wheat and Shreddies are made, at the former Nabisco factory (now part of Nestlé).