Previously to 1517 he became prior of the Dominican house at St. Andrews, and rose to be provincial of his order in Scotland before 1528.
In 1542 he is described as doctor of divinity, provincial, and prior of St. Andrews; he resigned the priory before 1552.
Echard says that he remained a firm Roman Catholic, and defended his faith by word and by deed.
According to Dempster, Grierson wrote: Some letters which are preserved in R. F. Plaudius's history of the order.
But Echard says that he had searched in vain for these letters, and it is possible that Grierson left no writings.