ELCHK Lutheran Secondary School (LSS) (Chinese: 基督教香港信義會信義中學) is a Lutheran aided mixed-sex secondary school in King's Park, Yau Tsim Mong District, Hong Kong established in 1958.

The school moved to its current location in 1964, near Yau Ma Tei station.

The school was founded by the Evangelical Lutheran Church of Hong Kong in April 1958 and initially borrowed 28B Grampian Road, Kowloon City, to operate, adopting a half-day timetable.

2 years later, as the church that owned the address stopped renting it out to the school, they moved to a vacated campus at 23 Ho Man Tin Hill Road.

The school has a non-standard campus, covering 13,000 square meters with 29 classrooms and various special-use rooms.