In the 1923 King's Birthday Honours, Ainsworth was appointed an Officer of the Order of the British Empire (OBE).[9] In June 1934, he was appointed an Officer of the Venerable Order of St John (OStJ).[10] In the 1935 King's Birthday Honours, he was appointed a Companion of the Order of the Bath (CB) in recognition of his service as Commandant of the Royal Army Medical College.[11] In December 1941, he was promoted to Commander of the Venerable Order of St John (CStJ).[12]