Sinclair User was a magazine dedicated to the Sinclair Research range of home computers, most specifically the ZX Spectrum (while also occasionally covering arcade games).

The magazine contained news, game reviews, previews, tips, help guides, columns, readers' letters, and cover-mounted game demos.

In earlier years, the magazine built up personality cults around some of its "hilariously" monikered staff, including Bill "Incorruptible" Scolding, John "Disgusting" Gilbert, Chris "Lunchbreaks" Bourne, Claire "Ligger" Edgely, Richard Price (writer of the "Gordo Greatbelly" adventure tips section), and columnist Andrew Hewson (founder of Hewson Consultants software).

Under David Kelly's editorial tenure, the magazine began to focus more on the gaming scene, and featured more colour graphics under designer Gareth "the Mad Celt".

By the time of editor Graham Taylor, the magazine included the cartoon character Kamikaze Bear, and the tone of the publication changed from a semi-serious magazine to something aimed more at children.