Henry Fowler was educated at Evesham grammar school and, from 1885 to 1887, at Mason Science College, Birmingham. Whilst there he gained a junior engineering diploma. Up until 1891 he was apprenticed under John Aspinall, chief mechanical engineer of the Lancashire and Yorkshire Railway at its Horwich works near Bolton. Shortly after the outbreak of the First World War in 1914, Fowler became secretary to the railway munitions committee and the following year was appointed director of production at the Ministry of Munitions. Three years after Fowler's return to railway work he became deputy chief mechanical engineer of the newly formed London, Midland, and Scottish Railway (LMS) in 1923 and two years later succeeded George Hughes as chief mechanical engineer.