Rainer Komers was born in Guben on 1 February 1944. He was active in the Student Film Club Bonn, where he was responsible for the design and printing of posters, among other things. He was also director of serigraphy at the Denise René/Hans Mayer Gallery and worked as a teacher for screen printing at the Kunstakademie Düsseldorf, where he then also started studying film studies, graduating with a Master’s degree. He also studied photography at the University of Essen.

From the end of the 1970s, Komers has been directing numerous short and feature-length documentaries and has been working on other filmmakers' projects as cinematographer. In 1979 he received the Ruhr Prize for Art and Science. A year later, at the Oberhausen Short Film Festival, Komers won the German Film Critics Award for his 38-minutes documentary "Zigeuner in Duisburg".

As a cinematographer, Komers repeatedly worked with director Peter Nestler, including on "Zur Geschichte der Juden in Frankfurt" (1988), "Pachama - Unsere Erde" (1995) and "Verteidigung der Zeit" (2007). He also did the camera work for Eva Heldmann's documentary "Five Sex Rooms und eine Küche" (2007), about the everyday lives of four prostitutes. In addition to his work in the film sector, he writes poetry, articles and essays (e.g. for German newspapers Die Zeit and the Süddeutsche Zeitung) as well as travelogues about India, Japan and Yemen. In 2006 he was awarded the Ruhr Prize for Art and Science for the second time.

Rainer Komers' best known works as a director include "Lettischer Sommer" (1992), "B 224" (1999, Hessian Film Prize 2001), "Nome Road System" (2005, German Short Film Prize in Gold), "Kobe" (2006) and "Milltown, Montana" (2009). His short documentary "Daugava Delta" (2014) won the main prize in the short film competition at the Big Sky Documentary Festival in Missoula (USA) in 2016. The half-hour documentary "Kursmeldungen" (2017), a foray through north German coastal landscapes between industrial aesthetics and nature, received an award in at the Short Film Festival in Oberhausen.

At the Visions du Réel Festival in Nyon (Switzerland) in 2018, Komers presented his long documentary "Barstow, California", a portrait of the small town of the same name on Route 66 in the Californian desert. At the Duisburg Film Week the film won the ARTE Documentary Film Prize; at the Festival achtung berlin 2019 it was awarded Best Documentary Film. In October 2019, "Barstow, California" was released in German cinemas.