He was consecrated a bishop by George Carey, Archbishop of Canterbury at Westminster Abbey on 6 December 2001, becoming the Bishop of Shrewsbury. He was chair of the Shropshire Strategic Partnership from 2006–2009. and was a member of the Rural Bishops' Panel from 2006–2009. In 2002 he completed his PhD as an external student of the University of Wales. For Lent 2006 Smith committed himself to living on the minimum wage. His election as Bishop of St Albans by the College of Canons of the Cathedral took place on 13 February 2009, and the confirmation of his election followed on 31 March. Smith's inauguration took place on 19 September 2009. From 2009 to 2011 he was joint chairman of the Anglican Methodist Working Party on the Ecclesiology of Emerging Expressions of Church which produced the report Fresh Expression in the Mission of the Church. For the centenary of the newly reconfigured Diocese of St Albans in 2014 he wrote Saints and Pilgrims in the Diocese of St Albans. On 4 November 2013 he took his seat in the House of Lords as one of the Lords Spiritual. He has spoken on a wide range of subjects in Parliament with a particular focus on rural matters, agriculture, housing, welfare, and problem gambling. He is President of the Rural Coalition.
Views
Smith is concerned about fixed odds gambling machines which fuel problem gambling, leading to people losing their homes, their savings and sometimes taking their own lives. Smith blames the UK government for not limiting the amount people can gamble on those machines to £2, Smith stated the government delay was out of step with, “politicians and campaigners are united in seeking the earliest possible introduction of the maximum £2 stake for FOBTs which will alleviate some of the devastating consequences of people addicted to gambling on them, some who can lose their homes and savings to them and then take their lives in desperation. Bookmakers taking huge profits and football clubs taking sponsorship from gambling and leaving the NHS to pick up the bill and families to face grief is privatising profit and nationalising consequences. It has to stop.” Smith also stated, “I am not anti-business. I am pro-victims. I am angry about impunity.”
He has contributed chapters to Changing Rural Life and Celebrating Community: God's Gift for Today's World. He has written Growing up in Multi-faith Britain: Explorations in Youth, Ethnicity and Religion, God-Shaped Mission: A Perspective from the Rural Church, and co-authored The Reflective Leader. He was joint editor of Faith and the Future of the Countryside.