His literary career began with contributions to Boy's Own Paper and other popular magazines. He authored more than 40 books, including:
- On Foreign Service (1900)
- Recollections of a Volunteer (1901)
- The Queen's Own (1902)
- The Red Coat Chronicles (1904)
- The Cruise of the "Cæsar" (1906)
- The Last Cruise of the "Monarch" (1908)
- The Adventures of a Naval Lieutenant (1909)
- The Fate of the Black Eagle (1910)
- The High Road of Empire (1911)
- The Green Field of France (1912)
- The Red Army (1913)
- The Secret Service (1914)
Dowling's works depicted the late 19th century British Empire and celebrated Victorian values of duty and service to the country. His stories often featured daring adventures and naval or military exploits set against the backdrop of real historical events.
In addition to his novels, Dowling also wrote historical nonfiction, such as Side Lights on the War in South Africa (1902) and With the Boer Forces (1901), reflecting his experiences during the Boer War. He also co-edited the Boy's Illustrated Paper.