No, Mr. does not mean married.
According to the provided reference, "Mister or Mr.: This is the term that is used to address men, whether they are married or unmarried. Abbreviate the term “mister” to “Mr.” if you are using it as part of a man's title." Therefore, Mr. is a title used to address men regardless of their marital status. It is simply an abbreviation of "Mister."
