Final answer:
The most populous Muslim country in the world is Indonesia, with a majority of its over 260 million population practicing Islam, making it the country with the largest Muslim population.
Step-by-step explanation:
Indonesia is the most populous Muslim country in the world. It has a significantly larger Muslim population than any Middle Eastern country, even surpassing densely populated Muslim nations like Pakistan and Egypt. In 2017, Indonesia's population exceeded 260 million, with the vast majority practicing Islam, which was introduced to the country in the 13th century and became the predominant religion by the 16th century. Due to Indonesia's extensive Muslim populous, it's known as the country with the largest Muslim population globally.