Q. Which country has largest majority of Shia Muslims?
Answer: Iran
Notes: The majority of Shia Muslims live in Iran, southern Iraq, Lebanon, Bahrain, Azerbaijan, and Yemen. Iran has the largest Shia population, with 66 million to 70 million Shias, or 37-40% of the world's total Shia population. Iraq, India, and Pakistan each have at least 16 million Shias. The four countries with a Shia-majority population are:

• Iran, where ~93% of Muslims are Shia
• Azerbaijan, where ~70% of Muslims are Shia
• Bahrain, where ~70% of Muslims are Shia
• Iraq, where ~67% of Muslims are Shia

There are also large Shia communities in Afghanistan, India, Kuwait, Pakistan, Qatar, Syria, Turkey, Saudi Arabia, and the UAE.