The most common blood type in humans is O positive (O+) , making up roughly one‑third to almost 40% of the global population and about 37–38% in many national blood-donor statistics.

Quick Scoop

  • Global winner: O+ is the most common blood type worldwide.
  • In many countries (like the U.S.): Around 37–38% of people are O+.
  • Why it matters: O+ blood can be given to any Rh‑positive person (A+, B+, AB+, O+), so hospitals keep a lot of it on hand.

Other common types

  • After O+, the next most common types in many populations are A+ and B+ , though exact rankings vary by region.
  • Some regions (like parts of Central and South America) have especially high rates of O types, while others (like parts of Europe or Asia) have more A+ or B+.

Rarest vs. most common

  • The least common standard ABO/Rh type in many datasets (such as in the U.S.) is AB‑ (AB negative) , while O+ remains the most frequent.
  • Because O+ is both common and widely compatible with other positive types, it is one of the most requested types for transfusions.

Information gathered from public forums or data available on the internet and portrayed here.