John Blanchard was born in 1932 on the Channel Island of Guernsey. Immediately before the German occupation of the island in the Second World War he was evacuated to Hebridean Island of Islay, off the west coast of Scotland. He returned to Guernsey in 1945.

After leaving school, he joined the Guernsey Civil Service, in which he worked for 13 years, eventually becoming H.M. Deputy Sergeant to the Royal Court of Guernsey.

Having been an active member of Holy Trinity Church, including serving for several years as leader of the young people's work, John Blanchard was converted to Christ in October 1954 under the ministry of the American preacher The Rev. Paul Cantelon.

In 1955 he became a co-founder of the Guernsey Branch of the National Young Life Campaign, from which over 20 members were called into full-time Christian service during the next seven years.

In 1962 he began his full-time preaching ministry, having been appointed as the South-West Union Evangelist of the National Young Life Campaign.

In 1965 he accepted an invitation to join the staff of the Movement for World Evangelization, in which his ministry widened throughout the United Kingdom and eventually took him to Europe and elsewhere. He continued on the MWE staff until the end of 1979, by which time he had been appointed as the organization's first Director of Evangelism.

In 1980 John Blanchard joined with two former MWE colleagues, Peter Anderson and Derek Cleave, in founding Christian Ministries, under whose auspices his evangelistic and Bible teaching ministry took him to many countries all around the world. In particular, he has paid numerous visits to the United States, where up to the present time he has conducted some 400 evangelistic missions and Bible teaching conventions.

In 2001 he received an honorary Doctor of Divinity degree from Pacific International University.

Christian Ministries came to an end in 2003, by which time John Blanchard had become committed to Popular Christian Apologetics, a project that involves writing, speaking, radio and television broadcasting and the production of a series of video tapes and audio cassettes providing a rational defence of the Christian faith. The PCA project now takes up virtually all of his time, but he also preaches and teaches in other evangelistic and Bible teaching situations.

John Blanchard is an internationally known Christian author, and his over thirty books include two of the UK's most widely used evangelistic publications, Right with God and Ultimate Questions. Published in 2000, his 655-page volume Does God believe in Atheists? was voted 'Best Christian Book' in the inaugural UK Christian Book Awards held in 2001.

John Blanchard is on the Board of Governors of Highland Theological College; is a Trustee and Life Vice-President of the Young Life; Patron of Liverpool City Mission and of the Society for the Protection of Unborn Children; on the Council of Reference of the Brighton & Hove City Mission; on the board of Reference of Orphaids, and Longhorsely Convention; and on the Council of Reference of Daylight Christian Prison Trust, Edinburgh Bible College and Truth in Science; and is a Patron of The Society for the Protection of Unborn Children..

John Blanchard and his wife Pam make their home in the village of Banstead, Surrey.