Klaus Hartmann was born on December 8, 1969 in Eisleben in Saxony-Anhalt. He grew up with his two siblings in a Protestant parsonage. Through the historical Eisleben, which was shaped by the Reformation period, and through his family - his uncle was a painting restorer - he learned about art history at an early age. A formative childhood memory for him was the annual Eisleben Wiesenmarkt, the largest amusement park in central Germany. He spent most of his school years in Halle, where he was friends with artists who supported him and where his interest in Africa was awakened. After completing the 10th grade, he trained as an orthopaedic shoemaker in Erfurt from 1986 to 1989. During this time, friends introduced him to the free jazz scene in Leipzig, where he was able to experience concerts by American avant-garde musicians such as Sun Ra and John Zorn. After the fall of the Berlin Wall, he studied "Free Art" with Werner Büttner at the University of Fine Arts Hamburg from 1991 to 1997.

In 1992 he travelled to Tanzania for the first time. Years later, this trip would trigger a series of Tanzania pictures. This was followed by an exchange semester at the Academy of Fine Arts in Vienna in 1994. Back in Hamburg, it was the seminars of the ethnologist Fritz Kramer that particularly interested him at the university. Long after his studies, he remained in touch with Kramer, who repeatedly advised him on his stays in Africa.

In the 90s, the University of Fine Arts Hamburg was a very lively, experimental house, a house of discussions, shaped by the conceptual art of the sixties and seventies. Teachers like Stanley Brouwn and Franz Erhard Walther taught minimalism, his teacher Werner Büttner addressed the view of the world, but the most important thing was the exchange and discourse between the students...

In 1998 he had his first solo exhibition at the Jürgen Becker Gallery in Hamburg. Since then his pictures have been shown in solo exhibitions at the Hamburger Kunsthalle, the Kunsthalle Bremerhaven, the Anhaltischer Kunstverein Dessau, the Nicole Klagsbrun Gallery New York, the Galerie Nosbaum Reding Luxembourg or in connection with artist residencies at the Modzi Arts Gallery in Lusaka or the NAFASI Gallery in Dar es Salaam, as well as in group exhibitions at the Alliance Française Dar es Salaam, the East Africa Art Biennale in Tanzania, Kenya, Uganda and Rwanda, the Hydra Workshop in Greece, the Kunsthalle Exnergasse Vienna, the Frankfurter Kunstverein and the Brandenburg State Museum for Modern Art in Cottbus and Frankfurt/Oder.

Klaus Hartmann's paintings are painterly constructions that arise from the artist's concrete observations and have biographical references. Scenes are often depicted with thematic breaks that can be read as views of society. The themes of his early paintings are blooming landscapes and lost places. He focused in particular on allotments, amusement parks, billboards, railway tracks, pedestrian bridges, bush formations or Chinese restaurants. Klaus Hartmann often traveled to East Africa and spent a few months in Zambia. Between 2006 and 2015, a group of Tanzania paintings consisting mainly of landscape images was created. The drawing series "Along the new road" has been created since 2016. The series is a collection of typical buildings that can be found in rural regions of Tanzania, Kenya, Rwanda and Zambia. The viewer slips into the role of a driver who fleetingly notices houses, huts and kiosks as he drives past. The landscape is fictional. A similar project was created in 2022 about houses along the TAZARA railway between Zambia and Tanzania. A new group of works is inspired by Hercules Seghers' fictional mountain landscapes. For this, Klaus Hartmann traveled to the Usambara Mountains in northern Tanzania and the hilly landscapes of Rwanda. In his bird paintings, he deals with exoticism and colonialism. He is particularly interested in the great egret, which was shot en masse in the colonies during the colonial period for the hat industry.

Paintings by Klaus Hartmann can be found in the Collection of Contemporary Art of the Federal Republic of Germany, the Brandenburg State Museum for Modern Art in Cottbus, the Bremerhaven Art Museum, the Deichtorhallen Hamburg/Falckenberg Collection as well as in private collections in Germany, the USA, Greece, Switzerland, Italy, India, Zambia, Tanzania and Luxembourg.