M
- Tzi Ma
- Christopher McDonald (actor)
- Scott MacDonald (actor)
- Dennis Madalone
- Barbara March
- Mark Margolis
- Jason Marsden
- Nan Martin
- Benito Martinez (actor)
- Jeff McCarthy
- Mart McChesney
- Carolyn McCormick
- Matt McCoy (actor)
- Gates McFadden
- Terrence E. McNally
- Robert Duncan McNeill
- Patricia McPherson
- Colm Meaney
- Luis Alfonso Mendoza (Latin American dub: additional voices)
- Eric Menyuk
- Arturo Mercado Jr. (Latin American dub: additional voices)
- Christopher Michael
- Joanna Miles
- Dick Miller
- Alan Miró (Latin American dub: additional voices)
- Maria Fernanda Morales (Latin American dub: additional voices)
- Glenn Morshower
- Marnie Mosiman
- Mugihito
- Diana Muldaur
- Warren Munson
Read more about this topic: List Of Star Trek: The Next Generation Cast Members