Langstaff Secondary School (LSS)^[1][2][3] is a public high school in Richmond Hill, Ontario, Canada.

Langstaff Secondary School is one of six schools in the York District to offer a French Immersion curriculum. Upon successful completion of the requisite French Immersion courses, students are eligible to receive a French Immersion Certificate.^{[citation needed]}

Langstaff Secondary School offers the Advanced Placement programme to its students. The school offers AP courses in Biology, English, French and Math (Calculus and Vectors). Like other AP programmes, students who complete the Grade 12 AP courses are eligible to write the AP exam.^{[citation needed]}

• Jonathan D'Aversa, hockey player for the Pittsburgh Penguins
• Gillian Ferrari, hockey player
• Melissa Lantsman, Member of Parliament for Thornhill
• Tracy Moore, TV personality
• Poorya Nazari, professional poker player
• Theo Peckham, former hockey player for the Edmonton Oilers
• Justin Trottier, political candidate, public speaker and media personality

• Education in Ontario
• List of secondary schools in Ontario

• Official web site of Langstaff Secondary School