The Two Graphs is a 1950 detective novel by John Rhode, the pen name of the British writer Cecil Street.

[1][2] It is the fiftieth in his long-running series of novels featuring Lancelot Priestley, a Golden Age armchair detective.

It was published in America by Dodd Mead under the alternative title Double Identities.

[3] Writing in The Observer Maurice Richardson noted a "slight slackening of tension towards the finish but an excellent specimen of Rhode’s later period."

In the Norfolk Broads one of a pair of identical twin brothers drowns, but it is not clear which one.