In the United Kingdom he is usually called "Stephen Donaldson" (without the "R").
Donaldson is part of the generation of fantasy authors which came to prominence in the 1970s and early 1980s. Like that of many of his peers, his writing is heavily influenced by the works of J. R. R. Tolkien. However, Donaldson's stories show a wide range of other influences, including Mervyn Peake, C. S. Lewis, Robert E. Howard, and even the operas of Richard Wagner. Donaldson is also a great fan of Roger Zelazny's Amber novels, which were a direct inspiration for his own Mordant's Need series. Also, in the Gradual Interview section of his website, Donaldson mentions his extensive study of Joseph Conrad, Henry James and William Faulkner to further develop his narrative style.