Final answer:
Muhammad was the first prophet to spread Islam. His wife, Khadija, was the first person to convert to Islam.
Step-by-step explanation:
The first prophet to spread Islam was Muhammad. In 610 CE, Muhammad began preaching and organizing the religion of Islam in the region of Mecca on the Arabian Peninsula. The teachings of the Prophet Muhammad, later compiled in the Holy Quran, built upon Judaism and Christianity. Muhammad's wife, Khadija, was the first person to convert to Islam after hearing his message.