Having grown up in a brass banding family, Dobson was educated at Launceston College where he was taught by the influential Rob Strike. Dobson moved to London at age 18 on a scholarship to study composition under Timothy Salter, Theo Verby and George Benjamin, at the Royal College of Music.

While at college, Dobson wrote music for many different ensembles including, wind orchestra, string orchestra, percussion ensemble and the RCM symphony orchestra. He received his first commission, from the London Philharmonic Orchestra in 2002 during in his second year of study. In 2004 he was a featured composer at the world-famous Three Choirs Festival and composed Sinewave, a contemporary work based on electronic music.

In 2002 Dobson also won the European Brass Band composers' competition in Brussells, which led to his being commissioned to write the test work for the 2003 English regional fourth section brass band competition, Lydian Pictures. A number of other commissions followed including a work for the national youth brass band finals of Great Britain, including a march for the BBC Music Live festival, and Brass Band Heritage Trust.

At RCM, Dobson was part of a group of students who formed 'Zone One Brass', a championship section band which he conducted for four years before moving away from London in 2004 after earning his B.Mus and graduating to the sounds of his own fanfare.

In 2007, Simon Dobson wrote the set piece for the European Brass band championships 'B' section, and his work The Drop, (based on Drum 'n' Bass DJ techniques), has been performed a number of times in some major concert venues, including the Birmingham Symphony Hall.

He has been Composer in Residence with both the Leyland Band, the Brighouse and Rastrick and the Fairey Band.

Dobson also works as a freelance conductor and is well known for his work with youth ensembles and players. His conducting led him to coach many of London's championship standard bands, taking him nationwide, as well as to Norway for the Norwegian Brass band championships in the NM 2008–11 and Switzerland. He worked with former national youth champions Mount Charles Youth Band, as well as the Devon County Youth band and the Cornwall Youth Brass Band, for whom he wrote his composition Penlee.