Robert William Thomson PRSSA FRSE (29 June 1822 – 8 March 1873) was a Scottish inventor known for inventing the refillable fountain pen and the pneumatic tyre.

Robert's father gave him a workshop, and by the time he was 17 years old he had rebuilt his mother's washing mangle so that the wet linen could be passed through the rollers in either direction, and had completed the first working model of his elliptic rotary steam engine which he perfected in later life.

He then went to work for an Edinburgh firm of civil engineers where he devised a new method of detonating explosive charges by the use of electricity, thus greatly reducing the loss of lives in mines throughout the world.

Thomson's "Aerial Wheels" were demonstrated in London's Regent's Park in March 1847 and were fitted to several horse-drawn carriages, greatly improving the comfort of travel and reducing noise.

They had two sons and two daughters including Courtauld Thomson and Elspeth, wife of Wind in the Willows author Kenneth Grahame.