Lesley University is a private university in Cambridge, Massachusetts, United States. It was founded in 1909 to educate teachers. Originally founded as a women's college, male students were admitted beginning in 2005.

The Lesley School (also known as Lesley Normal School) was founded by Edith Lesley in 1909 at her home at 29 Everett Street, Cambridge. The school began as a private women's institution that trained kindergarten teachers. It espoused the work of Friedrich Froebel, who invented the concept of kindergarten as a complement to the care given to children by their mothers. Teacher and writer Elizabeth Peabody opened Boston's first Froebel-inspired kindergarten in 1860; more kindergartens followed. Central to the Froebelian philosophy is the idea that individuals are important and unique, a focus that remains at Lesley University today.

Edith Lesley, after living in Panama and Maine and studying in Freiburg, Germany, moved to Boston and became involved in public school teaching. She completed kindergarten training, took courses at Radcliffe College, and then began to plan her own kindergarten training school. She wanted a school that would "consider the individual of basic importance; to inculcate the idea of gracious living; and to foster the tradition of American democracy." Now married, Lesley and her husband expanded the school by constructing an addition at the rear of their home, which today is known as Livingston Stebbins Hall. Around 1913, the Lesley School began training elementary teachers.

In 1941, the Lesley School reorganized under a board of trustees; in 1944, it received authority to award baccalaureate degrees and became known as Lesley College. In 1954, the college began to award graduate degrees; it later added majors in the fields of education, counseling, human services, global studies, art therapy, and management.

The School of Practical Art was founded by Roy Davidson in 1912. The school's early philosophy was based upon John Ruskin's words that it is "in art that the heart, the head, and the hand of a man come together" and Davidson's own belief that "beauty comes from the use." The school increasingly embraced the fine arts and developed a growing liberal arts curriculum; in 1967 the school was renamed The Art Institute of Boston (AIB) to acknowledge its increased focus upon fine art as well as design, illustration, and photography. In 1998, The Art Institute of Boston and Lesley College merged, setting the stage for the eventual formation of Lesley University, where AIB would become Lesley College of Art and Design.

Lesley became Lesley University in 2001. When university status was granted, the original colleges became the university's undergraduate units, while Lesley College's two graduate schools rounded out the university's four main academic units. In 2005, Lesley College (at that point, an all-female liberal arts college) became coeducational.

In 2006, the university acquired Prospect Hall, a former church listed on the National Register of Historic Places, with the goal of bringing The Art Institute of Boston to Cambridge. In 2007, Joseph B. Moore became president of Lesley. The following year, the university entered into a partnership with Episcopal Divinity School to jointly operate their Brattle Street campus and purchase several buildings. This move added dormitories, a dining hall, and classrooms, as well as expanded library services and administrative space.

In 2009, the university celebrated its centennial and embarked on its first major construction since the 1970s. Dormitories at 1 and 3 Wendell Street were added to the residential life offerings; both buildings are LEED Gold–certified.