Ragnar Sohlman was born in Stockholm, son to August Sohlman, a well-known newspaper man, and his wife Hulda Maria Sandeberg. In 1887, he enrolled at the Royal Institute of Technology in Stockholm and graduated as a chemical engineer in 1890.
In 1893 Sohlman became the assistant of Alfred Nobel in San Remo, and Nobel's will from 1895 named him and Rudolf Lilljequist as executors, with Sohlman expected to do most of the work. The will stated:
As Executors of my testamentary dispositions, I hereby appoint Mr Ragnar Sohlman, resident at Bofors, Värmland, and Mr Rudolf Lilljequist, 31 Malmskillnadsgatan, Stockholm, and at Bengtsfors near Uddevalla. To compensate for their pains and attention, I grant to Mr Ragnar Sohlman, who will presumably have to devote most time to this matter, One Hundred Thousand Crowns, and to Mr Rudolf Lilljequist, Fifty Thousand Crowns;— Alfred Bernhard Nobel, will dated Paris, 27 November 1895
The sum of 100.000 crowns was a very significant amount at the time, and made Sohlman a wealthy man. The amount can be compared to the prize amount of the first Nobel Prizes in 1901, 150.782 crowns each.
After Alfred Nobel's death on December 10, 1896, Sohlman was occupied for several years with the task of realizing Nobel's intentions of establishing the Nobel Prize. Since the will did not contain detailed regulations regarding selection of laureates and was contested by Nobel's relatives, the task kept Sohlman and his advisors occupied for several years. Sohlman was a member of the interim board of the Nobel Foundation.
He was the executive director of the Nobel Foundation 1929-1946.
Solhman's son was a Swedish diplomat and his grandson Michael Sohlman is the present executive director of the Nobel Foundation.