What is the most popular first name?

Mohammed. Spelled in various ways, such as Mohammed, Muhammed, etc. It is presently the most common first name on Earth.

The most common first names in America are James for males and Mary for females.

Actually, according to the US census, in 2007, these were the five most popular names in the US:

MALES: Jacob, Michael, Ethan, Joshua, and Daniel

FEMALES: Emily, Isabella, Emma, Ava, and Madison

Actually all of you are wrong the most common name for males is John and for females Isabella or Isabelle