Uetersen is a town located in the district of Pinneberg within the German state of Schleswig-Holstein. It is situated near the Elbe river along the small Pinnau River, positioned approximately 7 km (4.3 mi) south of Elmshorn and 30 km (19 mi) northwest of Hamburg.
The town is notable for being home to the Rosarium Uetersen. Established in 1929, it holds the distinction of being the oldest and largest rose garden in Northern Germany.