The Times Literary Supplement's review of 10 June 1926, began with "This is a well-written detective story of which the only criticism might perhaps be that there are too many curious incidents not really connected with the crime which have to be elucidated before the true criminal can be discovered". The review then gave a brief synopsis before concluding with "It is all very puzzling, but the great Hercule Poirot, a retired Belgian detective, solves the mystery. It may safely be asserted that very few readers will do so."
A long review in The New York Times Book Review of 18 July 1926, read in part:
There are doubtless many detective stories more exciting and blood-curdling than The Murder of Roger Ackroyd, but this reviewer has recently read very few which provide greater analytical stimulation. This story, though it is inferior to them at their best, is in the tradition of Poe's analytical tales and the Sherlock Holmes stories. The author does not devote her talents to the creation of thrills and shocks, but to the orderly solution of a single murder, conventional at that, instead. ... Miss Christie is not only an expert technician and a remarkably good story-teller, but she knows, as well, just the right number of hints to offer as to the real murderer. In the present case his identity is made all the more baffling through the author's technical cleverness in selecting the part he is to play in the story; and yet her non-committal characterization of him makes it a perfectly fair procedure. The experienced reader will probably spot him, but it is safe to say that he will often have his doubts as the story unfolds itself.
The Observer of 30 May 1926, said,
No one is more adroit than Miss Christie in the manipulation of false clues and irrelevances and red herrings; and The Murder of Roger Ackroyd makes breathless reading from first to the unexpected last. It is unfortunate that in two important points – the nature of the solution and the use of the telephone – Miss Christie has been anticipated by another recent novel: the truth is that this particular field is getting so well ploughed that it is hard to find a virgin patch anywhere. But Miss Christie's story is distinguished from most of its class by its coherence, its reasonableness, and the fact that the characters live and move and have their being: the gossip-loving Caroline would be an acquisition to any novel.
The Scotsman of 22 July 1926, said,
When in the last dozen pages of Miss Christie's detective novel, the answer comes to the question, "Who killed Roger Ackroyd?" the reader will feel that he has been fairly, or unfairly, sold up. Up till then he has been kept balancing in his mind from chapter to chapter the probabilities for or against the eight or nine persons at whom suspicion points. ... Everybody in the story appears to have a secret of his or her own hidden up the sleeve, the production of which is imperative in fitting into place the pieces in the jigsaw puzzle; and in the end it turns out that the Doctor himself is responsible for the largest bit of reticence. The tale may be recommended as one of the cleverest and most original of its kind.
Robert Barnard, in A Talent to Deceive: An appreciation of Agatha Christie, writes:
Apart — and it is an enormous "apart" — from the sensational solution, this is a fairly conventional Christie. ... A classic, but there are some better Christies.
Laura Thompson, Christie's biographer, wrote:
The Murder of Roger Ackroyd is the supreme, the ultimate detective novel. It rests upon the most elegant of all twists, the narrator who is revealed to be the murderer. This twist is not merely a function of plot: it puts the whole concept of detective fiction on an armature and sculpts it into a dazzling new shape. It was not an entirely new idea ... nor was it entirely her own idea ... but here, she realised, was an idea worth having. And only she could have pulled it off so completely. Only she had the requisite control, the willingness to absent herself from the authorial scene and let her plot shine clear.
In 1944–1946, the noted American literary critic Edmund Wilson attacked the entire mystery genre in a set of three columns in The New Yorker. The second, in the 20 January 1945 issue, was titled "Who Cares Who Killed Roger Ackroyd?"
Pierre Bayard, literature professor and author, in Qui a tué Roger Ackroyd? (Who Killed Roger Ackroyd?), re-investigates Agatha Christie's Ackroyd, proposing an alternative solution. He argues in favour of a different murderer – Sheppard's sister, Caroline – and says Christie subconsciously knew who the real culprit is.
In the "Binge!" article of Entertainment Weekly Issue #1343-44 (26 December 2014–3 January 2015), the writers picked The Murder of Roger Ackroyd as an "EW and Christie favorite" on the list of the "Nine Great Christie Novels".