Mickey Mason was a male Human of 20th century Earth. He was a professional athlete who participated in boxing contests.

In 1930, he fought Muggs Magoo in Bay Land Garden in San Francisco. Mason was the challenger. (DS9: "Past Tense, Part II")

This character was only mentioned in writing.
Mickey Mason replaced Ricky Mason on the boxing poster, which first appeared in "The City on the Edge of Forever".