Pearson joined Rolls Royce in 1932 becoming successively: Technical Production Engineer, Glasgow Factory, 1941; Chief Quality and Service Engineer, 1941-45; General Manager Sales and Service, 1946-49; Director, 1949; Director and General Manager, Aero-Engine Division, 1950; Managing Director, Aero-Engine Division, 1954-65; Chief Executive and Deputy Chairman, 1957-68; and Chairman and Chief Executive, Rolls-Royce Ltd, 1969-70.

In the 1960s Rolls Royce invested heavily in a new engine, the RB211, which it hoped would power a new generation of wide bodied jet aircraft. Initial problems with the financing of the engine led successively to Pearson's resignation as Chairman, the company being taken into state-ownership in 1971, and the subsequent flotation of the firm's motor car business in 1973 as a separate entity.

Pearson was a member of the National Economic Development Council 1964-1967, although note of the papers held by Churchill Archives Centre relate to this aspect of his activities. He was knighted in 1963.