Fritz Lau (1872–1966) was Low German writer, playwright and lyricist.

Fritz Lau was born on 10 August 1872 in the fishing village of Möltenort near the north German city port of Kiel. His father was a mariner and often away from home. According to Lau, his mother was a good storyteller, who also regaled Klaus Groth with her stories when he occasionally stopped by. Lau went to school in Altheikendorf and, at the age of 17, he entered the postal service where, after an initial job as an assistant in the Kiel area, he worked in many parts of Germany. He lived in Glückstadt from 1898 and retired in 1923. In his free time he was a writer in the Low German dialect. Publishing very little during the Nazi era, he released a final collection of stories in 1962: Wat löppt de Tiet. Utsöcht Vertellen. He died on 5 July 1966 in Glückstadt.

On 16 May 1955, the town of Glückstadt made him an honorary citizen. In his honour, his study was faithfully recreated in the Detlefsen Museum in Glückstadt.