According to Morris' daughter May it was the work he "held most highly and wished to be remembered by". Contemporary reviewers mostly agreed. In America The Atlantic Monthly compared it to Tennyson's Idylls of the King, writing that
Sigurd, the Volsung is the second great English epic of our generation...and it ranks after Tennyson's "Arthuriad" in order of time only. It fully equals that monumental work in the force and pathos of the story told, while it surpasses it in unity and continuity of interest.
Edmund Gosse, in The Academy, enthused: "The style he has adopted is more exalted and less idyllic, more rapturous and less luxurious – in a word, more spirited and more virile than that of any of his earlier works." The Literary World agreed that it was "the manliest and the loveliest work of Mr. Morris's genius", going on to predict that "Whatever its immediate reception may be, William Morris's Sigurd is certain eventually to take its place among the few great epics of the English tongue." The note of caution as to the reaction of the 19th century reading public was sounded more strongly by several other critics. Theodore Watts wrote in The Athenaeum, "That this is a noble poem there can be no doubt; but whether it will meet with ready appreciation and sympathy in this country is a question not so easily disposed of." He thought it "Mr. Morris's greatest achievement", but worried about the choice of metre, which he thought monotonous in effect. In an unfavourable review for Fraser's Magazine, Henry Hewlett complained that "The narrative seldom rises above mediocrity...the memory finds little to carry away, and the ear still less to haunt it." He was particularly repulsed by the Dark Age outlook he believed Morris to have adopted:
A poem...which, like Sigurd, reflects, with hard, uncompromising realism, an obsolete code of ethics, and a barbarous condition of society, finds itself irreconcilably at discord with the key of nineteenth-century feeling. Deprived of its strongest claim to interest, a sympathetic response in the moral and religious sentiment of its readers, it can only appeal to the intellect as a work of art, or as a more or less successful attempt at antiquarian restoration. It may be admired and applauded by the lettered few; but it will not be taken to the nation's heart.
By contrast, the North American Review believed it to be Morris's method "To reproduce the antique, not as the ancients felt it, but as we feel it,– to transfuse it with modern thought and emotion."
After Morris's death interest in his poems began to fade, but a few enthusiasts for Sigurd the Volsung continued to speak out in its favour. Arthur Symons wrote in 1896 that Sigurd the Volsung "remains his masterpiece of sustained power", and in 1912 the young T. E. Lawrence called it "the best poem I know" According to the philologist E. V. Gordon Sigurd the Volsung is "incomparably the greatest poem – perhaps the only great poem – in English which has been inspired by Norse literature", and George Bernard Shaw went so far as to call it "the greatest epic since Homer". However the novelist Eric Linklater, while acknowledging that "Morris tells his story with endless invention, with a brilliant profusion of detail", complained that the poem's "Thames-side heroism" conveyed too facile a sense of tragedy. It has never had a wide readership, and contemporary judgements on Sigurd tend to depend upon the judge's opinion of Morris's verse in general. Some find its length and archaic diction off-putting, but many modern critics agree with Morris that it is his finest poem.