Southend High School for Boys, also known by its initialism SHSB, is an 11–18 boys selective secondary Grammar school situated along Prittlewell Chase in Prittlewell, in the north-west of Southend-on-Sea, England. It teaches students from the age of 11 through to 18 years old, and admission to the school is dependent upon their performance in selective 11+ tests set by the Consortium of Selective Schools in Essex (CSSE). It converted to Academy status on 1 February 2011, and has autonomous control over itself. Student numbers have been increasing over recent years, and, as of academic year 2023–2024, just over 1,300 students on roll, with over 420 of them in the co–educational Sixth Form.

Southend-on-Sea, commonly referred to as Southend, is a coastal city and unitary authority area with borough status in southeastern Essex, England. It lies on the north side of the Thames Estuary, 40 miles (64 km) east of central London. It is bordered to the north by Rochford and to the west by Castle Point. It is home to the longest pleasure pier in the world, Southend Pier. London Southend Airport is located north of the city centre.