Electric light was installed in the entrance and courtyard at the early date of 1879, and Arthur Conan Doyle set the Sherlock Holmes stories A Scandal in Bohemia and The Sign of Four partly at the Langham.

The Langham continued throughout the 20th century to be a favoured spot with members of the royal family, such as Diana, Princess of Wales, and politicians including Winston Churchill and Charles de Gaulle.

One BBC employee who stayed at the Langham was Guy Burgess, one of the Cambridge Five, a spy ring that supplied official secrets to the Soviets during the Cold War.

A BBC internal memo reveals that upon being unable to access his room in the hotel late one night, Burgess attempted to break down the door with a fire extinguisher.

The hotel is hosting The Good Front Room, a popular long-term residency from Dom Taylor, which opened due to him winning the Five Star Kitchen TV show.

On 19 March 2010 Gyles Brandreth unveiled a City of Westminster green plaque commemorating the August 1889 meeting at the Langham between Oscar Wilde, Arthur Conan Doyle and Joseph Marshall Stoddart.

The Langham featured in Michael Winterbottom's film Wonderland (1999), in external shots for Mary-Kate and Ashley Olsen's made-for-TV movie Winning London (2001), and in Garfield: A Tail of Two Kitties (2006).