Books in Children's Book Series (sorted alphabetically)
- Marjorie's Vacation Carolyn Wells
- Mary Louise L. Frank Baum
- Mary Louise and Josie O'Gorman Emma Speed Sampson
- Mary Louise and the Liberty Girls L. Frank Baum
- Mary Louise in the Country L. Frank Baum
- Mary Louise Solves a Mystery L. Frank Baum
- Mary Ware's Promised Land Annie F. Johnston
- Meadow-Brook Girls Afloat; Or, the Stormy Cruise of the Red Rover Janet Aldridge
- Meadow-Brook Girls by the Sea; Or, The Loss of The Lonesome Bar Janet Aldridge
- Meadow-Brook Girls in the Hills; Or, The Missing Pilot of the White Mountains Janet Aldridge
- Meadow-Brook Girls Under Canvas; Or, Fun and Frolic in the Summer Camp Janet Aldridge
- Mother West Wind "How" Stories Thornton W. Burgess
- Mother West Wind's Children Thornton W. Burgess
- Mother West Wind "Where" Stories Thornton W. Burgess
- Mother West Wind 'Why' Stories Thornton W. Burgess
- Motor Boat Boys Mississippi Cruise; or, The Dash for Dixie Louis Arundel
- Motor Girls Margaret Penrose
- Motor Girls on a Tour Margaret Penrose
- Motor Girls on Cedar Lake; Or, the Hermit of Fern Island Margaret Penrose
- Motor Girls on Crystal Bay; or, The Secret of the Red Oar Margaret Penrose
- Motor Girls on Waters Blue; Or, the Strange Cruise of the Tartar Margaret Penrose
- Motor Girls Through New England; or, Held by the Gypsies Margaret Penrose
- Motor Maids at Sunrise Camp Katherine Stokes
- Motor Maids in Fair Japan Katherine Stokes
- Moving Picture Boys at Panama; Or, Stirring Adventures Along the Great Canal Victor Appleton