Ken Roczen (born 29 April 1994 in Mattstedt, Germany) is a German professional motocross and supercross racer.

In 2013, Roczen won the Supercross 250 West Championship, ending the season 2 points ahead of Eli Tomac.

Roczen finished the series 3rd in the points standings after the final race at Las Vegas.

By finishing 3rd overall in the Supercross points chase his first year on the 450, Ken showed that he was primed to become one of the sports top competitors.

Then on 21 Jan 2017, while running in 3rd place Roczen's foot slipped off of the footpeg while going over a triple and he was ejected from the bike in mid-air crashing hard and receiving a compound fracture to his left arm, after landing face-first in a rhythm section of the track.

Roczen would go on to miss the rest of the 2017 Supercross season and the following Motocross championship, as he had sustained serious injuries to his left arm including a compound fracture and compartment syndrome.

Unfortunately on 10 February 2018, in San Diego, Roczen suffered another serious crash while attempting to pass Cooper Webb.

He underwent surgery to repair the shattered bones, dislocation of the metacarpals, and torn ligaments in his right hand.

Luckily this gave Ken more time to allow his left arm to heal which was still damaged from the previous years crash.

He attended RedBull Straight Rhythm, taking away a victory in the 250cc class despite it being his first time racing a two-stroke in his pro career.

In 2020, on 11 January, Ken Roczen won his first AMA Supercross race in three years with a win at St.Louis.

The season resumed with seven rounds all in Salt Lake City, UT, between 31 May and 21 June racing Sundays and Wednesdays in Rice-Eccles Stadium without spectators.

After a string of poor results, Roczen decided not to race for the remainder of the AMA Supercross season due to mental and physical health reasons after a difficult start to the year.

Competing against seasoned riders, he contributed significantly to Team Germany's 4th place finish with scores of 10-8 for 2nd in the MX2 classification.

The 63rd version of the Motocross Des nations was held on 26 September 2010 at Thunder Valley in Morrison, Colorado.

Roczen along with Max Nagl & Marcus Schiffer, led Team Germany to their first win at this event.

The 2024 edition of the Motocross Des Nations was held at the Matterley Basin race track in Winchester, England.