His father was the actor Emanuel Reicher, born in Galicia, then part of the Kingdom of Austria. Emanuel married firstly the opera singer Hedwig Reicher-Kindermann: their son was the actor Frank Reicher. After Hedwig's death, he married the actress Lina Harf and the couple had three children: Hedwiga Reicher, Ernst, and Elly, who all worked as actors.
At Continental-Kunstfilm's studios Ernst Reicher acted, wrote scripts and directed films from 1912 to 1918. In December 1912 he starred in Vorglühen des Balkanbrandes, directed by Joe May. He wrote, directed and starred in two films: Das Werk in February 1913, and Die Statue in 1914, which was banned by the Berlin police censor until 1919. Starting in winter 1913/14, he wrote and starred in the first three of the 'Stuart Webbs' detective films, a popular detective series directed by Joe May for Continental. For more than a decade after 1914, Reicher continued to write and star as Stuart Webbs, and was closely identified with the part. It was not until 1918 that Reicher turned to other topics. On the first of April 1919, he moved the headquarters of his film company to Munich.
At the beginning of the twenties he suffered a serious car accident, in which he suffered a vertebral and fractured skull. Only from 1926 he appeared again on the screen, but he could no longer build on previous successes. After the seizure of power in 1933 by the National Socialists, Reicher emigrated to Prague, where he fell into obscurity. His last, tiny role in the 1936 French-language remake of The Golem was cut out of the final version. Later that year, he committed suicide by hanging in a Prague hotel room.
