High school is a term used in parts of the English-speaking world to describe institutions which provide all or part of secondary education, but not always the highest years of basic education, which can be called a "secondary school" or "secondary college" or other terms, depending on the nation or region (see below: Usage by country). The phrase "high school" is often incorporated into the name of the related institutions.

The term (as "high school") originated in Scotland, with the world's oldest being Edinburgh's Royal High School from 1505. The Royal High School was used as a model for the first public high school in the United States, the English High School founded in Boston, Massachusetts in 1821. The precise stage of schooling provided by a high school differs from country to country, and may vary within the same jurisdiction. In all of New Zealand and Malaysia along with parts of Australia, Bangladesh and Canada, high school is synonymous with secondary school, and encompasses the entire secondary stage of education.

Lower Merion Township is a township in Montgomery County, Pennsylvania and part of the Pennsylvania Main Line. As of the 2010 census, the township had a total population of 57,825. Lower Merion has the 5th highest per-capita income^{[citation needed]} and the 12th highest median household income^{[citation needed]} in the country with a population of 50,000 or more.

The name Merion originates with the county of Merioneth in north Wales. Merioneth is an English-language translation of the Welsh Meirionnydd.

Lower Merion Township was first settled in 1682 by Welsh Quakers who were granted a tract of land (the Welsh Tract) by William Penn. In 1713, Lower Merion was established as an independent Township with about 52 landholders and tenants. In 1900, the Township was incorporated as a Township of the First Class. Lower Merion is home to the oldest continuously used place of worship in the United States, the Merion Friends Meeting House, used continuously since 1695.

According to the United States Census Bureau, the township has a total area of 23.9 square miles (61.8 km²), of which, 23.7 square miles (61.4 km²) of it is land and 0.2 square miles (0.4 km²) of it (0.67%) is water.

Lower Merion High School, is a public high school in Ardmore, a community on the Pennsylvania Main Line.

It is one of two nearly equally-sized high schools in Lower Merion School District; the other is Harriton High School. Lower Merion serves both Lower Merion Township and the Borough of Narberth. It was ranked among the top 60 U.S. high schools, public or private, by The Wall Street Journal in 2005. In 2010, 1,378 students attended the school. The athletics teams are known officially as the "Aces," but the football team is called the "Bulldogs".

In 1894, with the consolidation of the area's three village high schools (Merion Square, Bryn Mawr, and Ardmore), Lower Merion began its first year in a stone building shared with the Ardmore Avenue Elementary School in Ardmore (photo). In 1897, nine students participated in the school's first commencement ceremony. The original high school faculty had seven members, including the principal and superintendent. The curriculum offered only a two-year preparation for either college or industry.