virtually all saudi citizens are muslim (officially, all are), and almost all saudi residents are muslim. estimates of the sunni population of saudi arabia range between 75% and 90%, with the remaining 10–25% being shia muslim. the official and dominant form of sunni islam in saudi arabia is commonly known as wahhabism (proponents prefer the name salafism, considering "wahhabi" derogatory) and is often described as 'puritanical', 'intolerant', or 'ultra-conservative' by observers, and as "true" islam by its adherents. it was founded in the arabian peninsula by muhammad ibn abd al-wahhab in the 18th century. other denominations, such as the minority shia islam, are systematically suppressed.