Thomas Sandell was born in 1959 in Pietarsaari, Finland but raised in Skellefteå, Sweden. He qualified as an architect from the Royal Institute of Technology in Sweden, and has worked both as interior architect and designer.
Sandell started his own business in 1990. His best known works as interior designer include furnishing the Moderna Museet in Stockholm, the London office of Ericsson and the new stock exchange building in Stockholm.

In 1995 Sandell founded the sandellsandberg agency together with Ulf Sandberg and Joakim Uebel. The agency strives to encompass architecture, design and advertising to create comprehensive solutions to clients’ requirements. Sandellsandberg employs about 60 people.

Thomas Sandell has designed products for several well-known brands, such as Cappellini, B&B Italia, Artemide, FSB, IKEA, Asplund, Offect, Laguna Light, Swedese, Gärsnäs and Källemo.

Sandell has received numerous awards from his work: Red Dot award 2002, Utmärkt svensk Form 1992, 1996, 1997, 2000; Design Yearbook 2002.