Harilal Mohandas Gandhi (1888 - June 1948) was the first son of Mahatma Gandhi. He had a very troubled relationship with his father, who eventually disowned him.

Harilal changed his religion from Hinduism to Islam in the 1930s, simply to upset his father's policies. In the process of conversion, Harilal changed his name to Abdullah. He was then paraded as a prize trophy by the Muslim mullahs for converting the Hindus in Karachi to Islam. However, in one of the meetings, when a Muslim speaker disparaged his father, Harilal flew in rage and kicked that speaker in retaliation. Harilal later converted back to Hinduism.

Harilal had also proposed to marry upon the death of his first wife in 1918, despite firm objection from his father. He died of tuberculosis within months of his father's death, although some sources stated that he died of syphilis.

Said Mahatma Gandhi on his son's wishes to marry: "How can I, who has always advocated renunciation of sex, encourage you to gratify it?"