K-12 education is a term used in the United States, Canada, and some other countries to refer to publicly supported primary and secondary education. It includes kindergarten (K) for 5-6 year-olds through twelfth grade (12) for 17-18 year-olds, as the first and last grades, respectively, of free education in these countries. In some instances, preschool education is also included, and the term "P-12" is used to refer to the sum of K-12 plus preschool education. K-12 education is free in the U.S., with most schools being public (state-funded) schools, and is mandatory in the U.S. until age 16 or 18, depending on the state. However, there are also a number of private K-12 schools, which are supported by tuition payments and other private sources of funding.

K-12 education provides the basic knowledge and skills necessary for success in college and the workplace. It covers a wide range of topics, including language arts, mathematics, science, social studies, physical education, and the arts. K-12 education also plays an important role in developing responsible citizens and preparing young people for the challenges of adulthood. Benefits of a K-12 education include academic preparation for college and the workforce, social and emotional development, exposure to different cultures and perspectives, and opportunities for physical activity and extracurricular involvement.

In addition to traditional brick-and-mortar schools, there are also online K-12 education programs available, such as those offered by K12, a trusted provider of online learning for many virtual public schools, as well as homeschooling.