Montessori education is an educational approach developed by Italian physician and educator Maria Montessori. Montessori developed many of her ideas while working with mentally challenged children. Her first school, La casa dei bambini, was opened to working class children in the slum neighborhood of San Lorenzo in Rome. Her approach was characterized by an emphasis on independence, freedom within limits, and respect for a child's natural psychological, physical, and social development.

Following her medical training, Dr. Maria Montessori began to develop her educational philosophy and methods in 1897, attending courses in pedagogy at the University of Rome and reading the educational theory of the previous two hundred years. In 1907, she opened her first classroom, the Casa dei Bambini, or Children's House, in a tenement building in Rome. From the beginning, Montessori based her work on her observations of children and experimentation with the environment, materials, and lessons available to them. She frequently referred to her work as "scientific pedagogy". In 1901, Maria Montessori met Alice and Leopold (Baroness & Baron) Franchetti of Città di Castello.

• Mixed age classrooms; classrooms for children ages 2 1⁄2 or 3 to 6 years old are by far the most common, but 0-3, 6-9, 9-12, 12-15, and 15-18 year old classrooms exist as well.
• Student choice of activity from within a prescribed range of options
• Uninterrupted blocks of work time, ideally three hours
• A constructivist or "discovery" model, where students learn concepts from working with materials, rather than by direct instruction
• Specialized educational materials developed by Montessori and her collaborators
• Freedom of movement within the classroom
• A trained Montessori teacher

As Montessori developed her theory and practice, she came to believe that education had a role to play in the development of world peace. She felt that children allowed to develop according to their inner laws of development would give rise to a more peaceful and enduring civilization. From the 1930s to the end of her life, she gave a number of lectures and addresses on the subject.

With the development of mobile touchscreen devices, several Montessori activities were made into mobile apps for children by companies such as L’Escapadou and Les Trois Elles.