Buddha was a kaafir philosopher not a Prophet
Question

                What is the Islamic ruling on one who says that Buddha was a Prophet?.
Praise be to Allah.
    Buddha was not a Prophet, rather he was a kaafir philosopher 
    who followed a religion that was not divinely-revealed. Whoever believes 
    that he was a Prophet is a kaafir. His people exaggerated about him and 
    believed that he was divine, and they worshipped him instead of Allaah. This 
    idolatrous Buddhist religion was adopted by many people in the past and in 
    modern times. The Muslim is obliged to dismiss this religion and its 
    followers, and to disavow himself of it and take a stand against them for 
    the sake of Allaah.

    And Allaah is the Source of strength. May Allaah send 
    blessings and peace upon our Prophet Muhammad and his family and companions. 
    End quote. 

    Standing Committee for Academic Research and Issuing Fatwas.