Like St Stephen’s Tavern this pub is a grade II listed building and is on the London Regional Inventory and the description is as follows: “Rebuilt in 1898-9 by architects Gardiner & Theobald in an eclectic Dutch-cum-Renaissance revival style. It’s a tall building on a small corner site which suggests the presence of a pub here for a very long time. The ground floor bar has been opened out into a long, single space but originally would have had a couple of drinking areas. The row of columns, glazed screenwork and different levels halfway down the bar suggest a partition at this point. Various good-quality fittings survive and the date of 1900 carved into the bar-back is a helpful record of when they were put in. The bar-back itself has 17th-century-style detail and lots of round arches. The counter has a series of unusually detailed panels with circle motifs. At the rear of the pub is some excellent etched and polished glass, and a reset panel announcing ‘saloon bar’. The ceiling decoration is very pleasing work with square panels and delicate swirling foliage. The ungainly structures sitting on the counters are modern pastiche. History across the road: Sir George Downing MP built Downing Street in the 1680s. Among those who had lodgings there was Dr Johnson’s companion, James Boswell. Nowadays only numbers 10, 11 and 12 remain. Number 10 has been the official residence of the Prime Minister since 1732. Interior alterations were designed by Sir John Soane in 1825 and in the late 1950s and early 1960s further alterations were made by Raymond Erith, the architect who designed the famous Hampstead pub, Jack Straw’s Castle, now, sadly, converted into residential flats.”

The listing description is as follows: “Public house on corner with Derby Gate. c.1890. Portland stone and granite ground floor, slate roof. Eclectic Flemish Baroque style. 4 storeys and gabled attic. Narrow single bay front to Parliament Street and 5-window return to Derby Gate. Ground floor retains unaltered public house frontage with basket handle arched bar windows and corner entrance under deep entablature-fascia; cut and frosted glass. Mullioned-transomed windows and pilaster mullioned 2-storey oriels above public house front to Parliament Street and to Derby Gate. String courses and shaped gable with sculpture surmounting composition. Pub interior retains most of original fittings with screens and shaped pediment shelving etc.”

The Red Lion featured on the Evening Crawl of Whitehall in August 2002, and the Four Lions, a Badger and the Garden of Eden: Evening Crawl of Westminster and St James's in August 2008.