Tadeusz Lucjan Gronowski (5 October 1894 in Warsaw–20 February 1990 in Warsaw) was a Polish graphic artist, architect who worked as an interior designer, painter, and a book illustrator.
He designed print advertisements for pre-WWII notable companies such as E.Wedel (chocolatier), Orbis Hotels (then a tourist agency) and Herse stores.
Gronowski took part in preparing the multi-color scheme (Polish: polichromia) on the tenements lining the Warsaw Old Town Square, and also worked in the city's theatres as a set designer.
He spent many of the years between the world wars in Paris, working as interior designer in charge of decor for prestigious and exclusive shops, including Galeries Lafayette.
He has received many Polish domestic and international prizes and acts of recognition, including the Grand Prix at the Exposition Internationale des Arts Décoratifs et Industriels Modernes in Paris (1925), and the gold medal for his design of Poland's pavilion at the 1939 New York World's Fair.