Hashim Khan was born in Nawakille in a small village near Peshawar. His father, Abdullah Khan, was the Head Steward at club in Peshawar where British army officers stationed in the area played squash. As a youngster, Khan served as an unpaidball boy at the club, retrieving balls that were hit out of court by the officers. When the officers had finished playing, Khan and the other ball boys would take over the courts.
In 1942, Khan became a squash coach at a British Air Force officers' mess. In 1944, he won the first All-of-India squash championship in Bombay, and successfully defended this title for the next two years. When Pakistan became an independent state, he was appointed a squash professional at the Pakistan Air Force, and won the first squash championship of Pakistan in 1949.
In 1950, Abdul Bari, a distant relative of Hashim Khan who had chosen to remain in Bombay after the partition of India and Pakistan, and who Hashim had beaten in several tournaments in India before partition, was sponsored by the Indian Government to play at the British Open where he finished runner-up to the Egyptian player Mahmoud Karim. This spurred Hashim Khan to seek backing to compete in the British Open the following year.
In 1951, Hashim Khan travelled to the United Kingdom to play in the British Open, and won the title beating Karim in the final 9-5, 9-0, 9-0. He again beat Karim in the final in 1952 9-5, 9-7, 9-0. He won again for the next four consecutive years, beating R.B.R. Wilson of England in the 1953 final, his younger brother Azam Khan in two tight five-set finals in 1954 and 1955 and Roshan Khan in the final of 1956. Hashim Khan was runner-up to Roshan Khan in 1957, and won his seventh and final British Open title in 1958, when he beat Azam in the final.
Hashim Khan also won five British Professional Championship titles, three US Open titles, and three Canadian Open titles. He settled in Denver, Colorado, and has continued to appear in veterans' matches at the British Open.
Hashim Khan had a total of 12 children. His eldest son Sharif Khan became a player on the North American hardball squash circuit in the 1970s, winning a record 12 North American Open titles. Four other sons Aziz, Gulmast, Liaqat Ali, and Salim also became hardball squash players.
On 18 August 2014, Hashim Khan died in his home in Aurora, Colorado due to congestive heart failure. He was widely believed to be 100 years old.