Starfleet commanders

In the history of Starfleet, there have been many officers holding the rank of commander (or the subordinate commander rank, lieutenant commander).

Gallery of unnamed lieutenant commanders
In addition, there was at least one more female lieutenant commander aboard the USS Enterprise (NCC-1701).

Background
Numerous officers were often referred to as commanders, or wore commander's rank insignia, but were actually other ranks. In, Jean-Luc Picard remembers meeting Lieutenant Commander Riker, but Riker was wearing commander's insignia in the corresponding scene in. This happened in TOS also, as Spock was referred to as an lieutenant commander in even though he regularly wore commander's stripes up to and including that point. The same went for Ben Finney in that episode and Giotto in, both of whom wore commander's insignia but were clearly referred to as lieutenant commander in dialog. The reverse happened to Chakotay, who wore lieutenant commander's insignia but was only referred to as commander for VOY's entire run.