Harilal Mohandas Gandhi converted to Islam in 1936, but later converted back to Hinduism.
According to an article published in the Times of India on December 30, 2014, Mahatma Gandhi's eldest son, Harilal, publicly converted to Islam on May 29, 1936, at the Jumma Masjid in Bombay. In a letter to his son, Gandhi wrote, "That does not make him a follower of the faith, though we should indeed feel satisfied if he truly practices in his life what is best in Islam… we should try to understand whatever religion we follow and bring credit to it." However, Harilal reportedly reconverted to Hinduism through the Arya Samaj in November 1936.
According to The Famous People website, which presents the life history and biography of famous people in various spheres of life, Harilal, who was born into an affluent family, fell in and out of alcoholism, embezzlement, prostitution solicitation, theft, and even got arrested several times for the same. The website also noted that Harilal cut ties with his family after his father imposed his characteristic simple, austere lifestyle on those around him. After converting to Islam, Harilal named himself Abdulla Gandhi. It is said that he converted to Islam because some Muslim leaders had promised to settle his debts.
The Indian Express wrote in 2008 that Harilal was not present at Gandhi's funeral in 1948. However, some reports said that he was there, but only a few people recognized Harilal due to his disheveled appearance.