The following is a list of baseball umpires with surnames beginning with the letters N through Z who officiated in Major League Baseball (MLB). The list includes those who worked in any of four 19th century major leagues (American Association, National Association, Players' League, Union Association), one defunct 20th century major league (Federal League), the currently active Major League Baseball, or either of its leagues (American League, National League) when they maintained separate umpiring staffs. All of the above leagues, with the exception of the National Association, are recognized by MLB's Special Baseball Records Committee. The NA's status as a major league is disputed, with some researchers such as those involved with Retrosheet including it in their major league statistics.