Wahhabi (Arabic: Al-Wahhābīyya الوهابية) or Wahhabism is the conservative form of Sunni Islam practised in Saudi Arabia and Qatar. People think Muhammad ibn Abd-al-Wahhab, an 18th century scholar, started this belief. He wanted to see a return to the practices of the first three generations of Islamic history.

Some definitions or uses of the term Wahhabi Islam include:

• "a corpus of doctrines, but also a set of attitudes and behavior, derived from the teachings of a particularly severe religious reformist who lived in central Arabia in the mid-eighteenth century". Gilles Kepel.
• "pure Islam that does not deviate from Sharia law in any way and should be called Islam and not Wahhabism". Prince Salman bin Abdul Aziz, the governor of the Saudi capital Riyadh.
• "a misguided creed that fosters intolerance, promotes simplistic theology, and restricts Islam's capacity for adaption to diverse and shifting circumstances". David Commins, paraphrasing opponents' definition.