Sheikh Ismail was born on 17 Shaaban 1311 Hijra. He was the son Haji Muhammad Salleh bin Haji Hashim and a great-grandson of Haji Ishak, the founder of the pondok school in Pulau Pisang and the Chief Kadi of Kubang Pasu during the reign of Tunku Anom.

He received his early education from his father in the pondok school of Pulau Pisang. In 1330 Hijra, he went to Mecca with his father where he continued his study at the Haram Mosque. Upon the conclusion of his studies there, he went on to the Al-Azhar University, in Cairo, for further studies. He studied from 1346 Hijra to 1351 Hijra and graduated with an Ahliatul Qarbak degree. His tutors were sheikh Abdul Wasif and Sheikh Al-Maliki. While in the Middle East he visited Palestine before returning to Mecca in 1352 Hijra.

He returned to Kedah in 1353 Hijra and was asked by Haji Muhammad Salleh to teach in the pondok school of Pulau Pisang. He served as a senior teacher with Dr. Burhanuddin Helmi. The Pondok Religious School of Pulau Pisang was renown even in Indonesia. It had a student population of between 800 to 1000 people. Sheikh Ismail did not serve long as a teacher. He was soon appointed as Inspector of Kedah Religious Schools by His Highness Tunku Mahmud Ibni Almarhum Sultan Ahmad Tajuddin Mukarram Shah. While he was in office, he worked on improving the system in religious schools and his rules and guidelines were still being followed to this day.

He wrote many books on the system and the rules related to the running of religious schools at that time. Unfortunately, most of those useful books were lost and only two could be found. They were the Hidayat-an-Nufus and the Tarbiyat-ul-Auladiyah. The Hidayat-an-Nufus contained a collection of the words used in praying and these were closely analyzed, and their proper use informed so that the public could get the best out of the traditions performed the Prophet himself. The Tarbiyah Auladiyah, on the other hand, informed the public on the good of Islam as a way of life, so that one could reach haqppiness and contentment in the world and the hereafter.

In 1356 Hijra, he was appointed as Kedah's Chief Kadi. He served for two years. During those two years, he made a contributed greatly to the spread of Islam. In spite of his busy schedule, he always made time to visit and teach at his father's ( Haji Muhammad Salleh) pondok school of Pulau Pisang. He contributed his ideas, energy as well as money to raise the standard of the school so that it could become a center of learning. Sheikh Ismail was the person responsible for renaming the school, Madarsah Ishakiah and at the same time modernize it system of education to suit the time.

In1358 Hijra, Sheikh Ismail became the chairman of the Kedah Sheih-ul-Islam Council. He served until 23 Shawal, 1364 Hijra. His greatest achievement while holding the post was the formation of the State's Zakat Department, which had the responsibility of collecting and distributing zakat to the eight deserving groups. The department was formed by the order of His Highness Tunku Mahmud Ibdni Almarhum Sultan Ahmad Tajuddin Mukarram Shah. To legalize the formation of the Department, a bill had to be prepared, indicating how the zakat were to be collected and distributed so that the running of the department was in line with the teachings of Islam. All this was done by Sheikh Ismail with the aid of two other Ulamas, Haji Yaakub Haji Ahmad (Yaakub Puteh) the kadi of Alor Setar District, and Haji Abd. Ghani bin Haji Awang, Kedah's Chief Kadi.

When the Japanese occupied Malaya for three years and eight months, Sheikh Ismail worked tirelessly to ensure that Islam would not be violated by the occupiers. He tried to influence the Japanese into protecting Islam when he was given the chance to speak at a Congress of Representatives of Islamic Organizations held on April 5, 1943, in Singapore. As an Ulama and a Nationalist, he was one of the persons responsible for persuading the Japanese to return the position and the power of the Sultan. On January 21, 1943, Sheikh Ismail was appointed as a representative of the Sultan in a conference between the Japanese and the Malay Rulers, held in Sumatra and Singapore. It was at this opportunity that he gave his heartfelt plea that for the Malays to be protected for the power of the Malay Rulers to be returned as a symbol of Malay unity.

Sheikh Ismail died on 23 Shawal 1363 Hijra at the age of 53, a year after the passing of his father, Haji Muhammad Salleh. He was buried at the Pulau Pisang Mosque Cemetery, near both his father and grandfather. His younger brother, Haji Kassim continued his effort to make the Pulau Pisang Pondok Religious School a great center of learning.