Theo Nieuwenhuis (Noord-Scharwoude, 1866 – Hilversum, 1951) was a versatile Dutch artist, designer and designer, who played an important role in the development of Dutch Art Nouveau – also known as Nieuwe Kunst. He was active at the interface between visual arts and applied arts and is considered one of the key figures within the decorative art movement around 1900.

Nieuwenhuis was born in Noord-Scharwoude in North Holland and studied at the Rijksakademie van Beeldende Kunsten in Amsterdam. He became fascinated at an early age by the ideals of Gesamtkunst: the idea that art should permeate all aspects of life. He found expression in this pursuit in a wide range of disciplines – from furniture design and book decoration to ceramics, painting, textiles, interior decoration and graphic design.

Together with artists such as Gerrit Willem Dijsselhof and C.A. Lion Cachet, he was closely involved in the artistic renewal of interior design in the Netherlands. His designs for furniture, wallpaper, fabrics and utensils were often richly decorated, inspired by flora, fauna and oriental ornamentation, but always carefully balanced in form and line.

Nieuwenhuis also left a lasting impression in the graphic arts. His book covers, typography and illustrations for publishers such as Versluys and the magazine De Kroniek bear witness to a great stylistic unity and love of detail. He also designed posters, ex libris and even stamps.

Theo Nieuwenhuis was not a painter in the traditional sense, but a versatile artist who blurred the boundaries between art and craft. His work was in the service of beauty and harmony, with a deep conviction that art could and should enrich daily life. He remained active and involved in the world of applied art until old age.

His legacy lives on in museum collections, including the Rijksmuseum and the Stedelijk Museum Amsterdam, where his designs are considered masterpieces of Dutch Art Nouveau.