Olli Dittrich was born in Offenbach on November 20, 1956. He was raised in Hamburg, and completed an apprenticeship as a stage painter at the Hamburg opera house, though would not continue to work in this profession. Instead, he took a job as a packer at the Deutsche Grammophon record company, where – over the course of seven years – he made it to the position of product manager. Dittrich, who plays guitar, piano and drums, also trained as a singer and from 1982 on, he moonlighted as a composer, guest vocalist and design artist. He composed over 200 songs, including works for James Last, Annette Humpe and Die Prinzen. He also sang and played in several bands and recorded a solo album under the moniker TIM.

In 1991, Olli Dittrich met comedian Wigald Boning, with whom he would later work on numerous skits and eventually found the band "Die Doofen". In 1992, Dittrich made his appearance on stage of the Hamburg Quatsch Comedy Club. Alongside Boning, he was an original cast member of the TV comedy show "RTL Samstag Nacht" from 1993 until 1998. In 1995, Dittrich and Boning released the second album of "Die Doofen": The record, titled "Lieder, die die Welt nicht braucht", went on to sell one million copies and was a huge chart success.

After leaving "RTL Samstag Nacht", Dittrich got his first own TV show "Olli, Tiere, Sensationen", which was cancelled after two seasons due to poor ratings. Much more successful, was the improvisational comedy format "Blind Date" (2000-2006), which partnered Dittrich with comedian Anke Engelke and garnered multiple awards. Since 2004, Dittrich plays the titular character of the TV show "Dittsche", another improvisational format which focuses on an unemployed and somewhat tragic slacker who spends his nights reminiscing at the counter of a take-away, The series won both the German TV Award and the Grimme Award. In 2011, Dittrich published the autobiography "Das wirklich wahre Leben".

Over the years, Dittrich also had notable supporting roles in theatrical releases, including "Frau Rettich, die Czerny und ich" ("Mrs. Rettich, Czerny and Me", 1998), the satire "Late Show" (1999) and the thriller spoof "Der Wixxer". Cast against type, he also convinced as Joseph Goebbels in Jo Baier's made-for-TV drama "Stauffenberg" (2004). Dittrich was also part of the ensemble cast of Otto Waalkes' comedies "7 Zwerge – Der Wald ist nicht genug" ("7 Dwarves – The Wood is Not Enough") and "Otto's Eleven" (2010).

Dittrich had his first leading screen role opposite Katja Riemann in Otto Alexander Jahrreiss' "Die Relativitätstheorie der Liebe" (2011). Two years later, he starred in the feature film release "König von Deutschland" ("King of Germany"). Also in 2013, his new comedy series "Frühstücksfernsehen" premiered on network television.