Heidi Kristina Blomstedt (née Sibelius; Järvenpää, 20 June 1911 – Helsinki, 3 January 1982) was a Finnish designer.She graduated in ceramics at the Taik School of Art and Design in 1932, and worked as a freelance ceramist and for the Arabia company.
She married the architect Aulis Blomstedt, and they had four children: Juhana Blomstedt (1937–2010), Petri Blomstedt (1941–1997), Anssi Blomstedt (b.
1945) and Severi Blomstedt (b.
1946).Her parents were the composer Jean Sibelius and Aino Sibelius.