Mahadev Desai (1 January 1892 – 15 August 1942) was an Indian independence activist and writer best remembered as Mahatma Gandhi's personal secretary. He has variously been described as "Gandhi's Boswell, a Plato to Gandhi's Socrates, as well as an Ananda to Gandhi's Buddha".
Mahadev Desai was born on 1 January 1892 in the village of Saras in Surat District of Gujarat to Haribhai Desai a school teacher and his wife Jamnabehn. Jamnabehn died when Desai was only seven years of age. In 1905, aged 13, Mahadev was married to Durgabehn. He was educated at the Surat High School and the Elphinstone College, Mumbai. Graduated with a BA Degree, he passed his L.L.B in 1913 and took job as inspector in central co-operative bank in Bombay.
Mahadev Desai first met Gandhi in 1915 when he went to meet him to seek his advice on how best to publish his book (a Gujrati translation of John Morley's English book On Compromise). Desai joined Gandhi's Ashram in 1917 and with Durgabehn accompanied him to Champaran that year. He maintained a diary from 13 November 1917 to 14 August 1942, the day before his death, chronicling his life with Gandhi. In 1919 when the colonial government arrested Gandhi in Punjab, he named Desai his heir. Desai was for the first time arrested and sentenced to a year in prison in 1921. He was Gandhi's personal secretary for 25 years, but as Verrier Elwin wrote of him, "he was much more than that. He was in fact Home and Foreign Secretary combined. He managed everything. He made all the arrangements. He was equally at home in the office, the guest-house and the kitchen. He looked after many guests and must have saved 10 years of Gandhi's life by diverting from him unwanted visitors".Rajmohan Gandhi writes of Mahadev Desai thus: "Waking up before Gandhi in pre-dawn darkness, and going to sleep long after his Master, Desai lived Gandhi's day thrice over — first in an attempt to anticipate it, next in spending it alongside Gandhi, and finally in recording it into his diary".