Which typeface was commissioned for the London Underground and introduced in 1916?

Johnston Sans was commissioned for the London Underground and introduced in 1916.

The typeface was created by calligrapher and designer Edward Johnston for London Underground’s publicity and signage. Its clean, distinctive letterforms improved consistency across posters, maps, station signs and printed material. The design became a major part of the organisation’s visual identity alongside the roundel.

Johnston Sans was deliberately highly legible rather than ornate. Its lowercase letterforms, including the distinctive diamond-shaped dot over the i, helped give Underground communications a unified appearance.

Gill Sans is a common wrong answer because it was also an influential British sans-serif typeface and was designed by Eric Gill, who had worked with Johnston. However, Gill Sans was not the typeface commissioned for the Underground. The original Johnston design has been revised over time, including versions known as New Johnston.