An Australian by birth, Wyly Grier studied in Paris with Bouguereau, Robert-Fleury and Legros.

He and his younger brother Louis GRIER both spent some time in St Ives, although Wyly's time there seems lesser known. The brothers lodged together at 6 The Terrace, St Ives.

One of the first members of the newly formed St Ives Art Club (STIAC) in 1890, Wyly took part in cricket matches on the side of St Ives against the Newlyn artists. In the studio lettings section of Lanham's advertisements of 1892, it was announced 'To be let, Mr Wyly Grier's magnificent studio overlooking Porthmeor Beach'.

In 1894 he was living on King's Road, Chelsea in London, and by 1896 his address was c/o Chapman Bros, also on King's Road, Chelsea for sending-in to the RA, suggesting that he was no longer resident in St Ives. By the 1902 edition of The Year's Art, his name and address had disappeared from English record; he then, however, exhibited at the Royal Canadian Academy (Ottawa). He died in Toronto, Ontario.