A Swedish painter and illustrator, Lagerstedt was born in Agunnaryd, Kronoberg County. In the 1910s he studied at the Slöjdföreningen school and The Valand Academy of Fine Arts, where Gunnar Hallström , Anders Trulson and Axel Erdmann were his tutors. After military service in the Great War, he studied art in Copenhagen. He then travelled south in the company of fellow painters Torsten Palm, Hugo Zuhr and Sixten Lundbohm and painted intensively in Spain and Morocco. In Paris he studied under André Lhote.

Lagerstedt exhibited publicly from 1921 and held regular solo exhibitions in Sweden and abroad. He participated in the now defunct art category in the 1932 and 1936 Olympic Games. He was a talented illustrator and became one of Sweden’s most sought after cartoonists.

He was drawn to movement and theatre – particularly sporting events and the drama around them. Boxing was a recurring theme in the 1930s and his major painting of a Boxing Match, his entry into the 1932 Los Angeles Olympics, was sold through Panter & Hall to a private collection a few years ago. His paintings hang in the collections of the Swedish National Museum, the Museum of Performing Arts and the Drawing Museum in Laholm.