Maitland died there, and Smeton went on to Geneva, where he conversed with the reformers, and finally decided to leave the Roman Catholic church.
In 1577 he returned to Scotland, and was appointed minister of Paisley Abbey and dean of faculty to Glasgow University.
On 3 January 1580 James VI appointed him principal of Glasgow University, in succession to Andrew Melville.
Smeton was author of Ad Virulentum Archibaldi Hamiltonii Apostatae Dialogum, de Confusione Calvinianae Sectae apud Scotos, impie conscriptum.
With this work was a life of John Knox, Eximii viri Joannis Knoxii, Scoticanae Ecclesiae Instauratori, vera Extreme Vitae Obitus Historia.