Samuel George Soal (1889–1975) was a British mathematician and parapsychologist. He was charged with fraudulent production of data in his work in parapsychology.

Soal graduated with first class honours in mathematics from Queen Mary College (then East London College) in 1910. After service in World War I, in which he suffered shelling at the Battle of the Somme, he lectured in mathematics at Oxford in the Army School of Education, before returning as a lecturer to Queen Mary College, University of London. In 1944, he was awarded the D.Sc. from Queen Mary College, where he continued to lecture in mathematics until his retirement in 1954. In 1947, he presented the Ninth Myers Memorial Lecture to the Society for Psychical Research, largely on the topic of the card-guessing experiments he had been recently conducting. He served as president of the Society for the years 1950-1952. He was a Fulbright Scholar in 1951, for which he journeyed to the USA to work with J. G. Pratt at Duke University. He was awarded an Honorary Fellowship in Psychology at Birkbeck College, University of London for the years 1954-1958. Thereafter, he moved permanently to Caernarvonshire, Wales, where he had routinely holidayed for each year over the past few decades, and where he died in 1975.

During this time, Soal demonstrated a personal as well as scientific interest in psychical research, becoming a member of the Society for Psychical Research in October 1922. He was partly moved to make his first parapsychological studies following the death of one of his brothers in the First World War. Like many of the bereaved at the time, he made enquiries of mediums concerning communication with the departed; but conducted his observations with a scientific approach. His observations surprised conventional understanding even within psychical research. Most especially, he reported a case of apparently precognitive telepathy of a situation yet to occur for a long-forgotten, but still living, friend of his, Gordon Davis. This suggested, in line with earlier speculations, that the statements of mediums had nothing to do with "spirits of the departed," but only knowledge gained - by telepathy, if need be - from the sitters themselves. What was particularly surprising was that this information was yet to be learned by Soal himself.

Soal himself practised automatic writing at this time, and pseudonymously authored a much-discussed paper on the scripts he produced, which purported to be authored by the deceased Oscar Wilde. He later himself declaimed the evidentiality of these scripts, and considered that they were largely the product of cryptomnesia.

Soal moved to a more statistical and controlled approach, firstly by conducting an experiment in which up to a few hundred persons participated at one time. This involved Soal and a small group of agents enacting a scenario, playing with a certain object, reciting a poem, and so on, which the participants, situated across Great Britain and other countries, were required, at the same time, to attempt to imaginally perceive. The French psychical researcher Rene Warcollier contributed some trials to this research, via his pool of selected participants. While some striking correspondences were obtained, these did not hold up to Soal's statistical scrutiny, and the report of the research commenced with the note that the findings were "entirely negative".

Following popular and academic reports of extra-sensory perception by card-guessing, Soal again changed his research processes and commenced a series of card-guessing experiments in telepathy, including trials canvassed over radio and via the literary magazine John O'London's Weekly. From 1936-1941, he performed over 120,000 trials of card-guessing with 160 participants, finding no evidence of supernatural abilities. In review, he scathingly offered the opinion that telepathy was a merely American phenomenon; he was described by the US researcher, J. B. Rhine, as one of his most harsh and unfair critics.

Next however, upon the hypothesis of Whately Carington, a fellow researcher within the Society for Psychical Research (SPR), Soal was able to report a significant displacement effect in his data for two of his earlier participants. Carington and Soal co-authored a paper on the effect, published in Nature in 1940. Soal thereupon sought to confirm these observations with new studies with these participants: Basil Shackleton (a celebrated London portrait photographer, later to become associated with the "Grape Cure" for cancer) and Gloria Stewart. It was reported that Stewart performed better at chance at naming the card ahead and behind the target card; however, this was not the task, nor was it her intention.

These studies, conducted in collaboration with K. M. Goldney and F. Bateman, were widely reviewed as among the most challenging proofs of precognition and telepathy. Not only were the significances of the studies - in terms of the correspondence between ESP guesses and random targets - extraordinary, the procedures appeared to allow no alternative hypothesis. There was also the testimony of 21 prominent observers who, individually, monitored Soal's work with Shackleton, that they were satisfied with the conditions, and could conceive of no means by which the results could be obtained by normal means other than ESP. Many leading academics, including C. D. Broad and Sir Cyril Burt, were persuaded, largely or partly on the basis of these reports, to lend academic support to psi-related ideas and research.