Since its formalization in the book The Nature of Prejudice published in 1954, Gordon Allport’s contact hypothesis has been one of the most influential theories in social psychology. Researchers have revisited the cognitive, emotional, and sociocultural psychological mechanisms that Allport outlined as responsible for altering prejudices toward members of outgroups. Over the past two decades, peace psychologists have suggested that the contact hypothesis can be used in real-world interventions. To date, however, there has been no review of studies that report the contact hypothesis with respect to Islamophobia. This chapter reviews Allport’s theories and analyzes peer-reviewed academic studies that measure the relationship between non-Muslims coming into contact with Muslims and prejudice toward Muslims. Nearly all studies report that non-Muslims who have positive contacts with Muslims demonstrate more favorable, less prejudiced attitudes toward Muslims as a whole. Some studies also report that non-Muslims who have negative contacts with Muslims experience greater prejudice. The limitations of extant studies and future research directions are also discussed.