Mar Joy Alappatt was born at Parappukara, in Thrissur district, Kerala, India, on September 27, 1956 as the second son of late Mr. Varghese and late Mrs. Rosy Alappatt. He has two brothers and two sisters. His baptismal name is John and he is named after the patron saint of his parish, St. John Nepomucene. He is commonly known as Fr Joy Alappatt. He had his primary School at St. George Lower Primary School, Puthenpally, Varapuzha; his Upper Primary School at A.U.P.S., Parappukkara, and his high school at P.V.S. High School, Parapukkara.
Holy Father Pope Francis appointed Rev. Fr. Joy Alappatt, Pastor of Mar Thoma SleehaSyroMalabar Cathedral, Chicago as the Auxiliary Bishop of St. Thomas SyroMalabar Catholic Diocese of Chicago on July 24, 2014. The appointment was communicated by Archbishop Carlo Maria Viganò, Apostolic Nuncio to the United States on July 23, 2014. His titular see is Bencenna.
As an Auxiliary Bishop, he will be serving the St. Thomas SyroMalabar Catholic Diocese of Chicago, together with Mar Jacob Angadiath, Bishop of the diocese.