Marriott joined the Straits Settlement Civil Service in 1896 as a cadet[4] and rose to the high position of Colonial Secretary before retiring in 1928.
[7][8] From 1912 to 1920, Marriott was appointed as Private Secretary to the Governor and the High Commissioner of Malay States, Sir Arthur Young.
Marriott also held several posts of Auditor General, Secretary to the High Commissioner and Custodian of Enemy Property, in additional to his own duty, during the time of shortage of manpower due to the World War I.
After over thirty years of service in the British Empire, Marriott intended to retire as a Colonial Secretary of the Straits Settlement at the end of 1927.
Due to change in the Governor during the middle of 1928, Marriott stayed on for the entire of 1928 to enable Sir Hugh Clifford to take leave in July 1928 with the knowledge that the Government is in safe and experienced hands.