Here are lists of single-sex education (schools which only admit boys, or those which only admit boys at certain levels/years/grades), or those which follow the Diamond Schools model (separating students by gender at points), by country.

Tasmania

• The Hutchins School
• St. Virgil's College

Australian Capital Territory

• St Edmund's College, Canberra
• Marist College, Canberra

New South Wales

• St Aloysius' College
• Ashfield Boys High School
• Asquith Boys High School
• Balgowlah Boys Campus
• Blacktown Boys High School
• Canterbury Boys' High School
• Christian Brothers College, Burwood
• Christian Brothers High School
• Cranbrook School
• James Cook Boys Technology High School
• Epping Boys High School
• Farrer Memorial Agricultural High School
• Homebush Boys High School
• The Kings School
• Knox Grammar School
• Normanhurst Boys' High School
• Punchbowl Boys High School
• Randwick Boys High School
• Saint Ignatius' College Riverview
• Sydney Boys High School
• Sydney Church of England Grammar School
• Trinity Grammar School Summerhill

Queensland

• The Southport School Gold Coast
• Marist College Ashgrove
• Moreton Bay Boys' College
• St. Joseph's Nudgee College
• Brisbane Boys College
• Anglican Church Grammar School
• Brisbane Grammar School
• Padua College
• St Augustine's College (Queensland)
• St. Brendan's College, Yeppoon
• St Joseph's College, Gregory Terrace
• St Laurence's College

Western Australia

• Hale School
• St Peter's College
• Aquinas College Salter Point
• Christ Church Grammar School, Claremont
• Mazenod College, Lesmurdie

Victoria

• Brighton Grammar School
• Melbourne High School
• Scotch College, Melbourne
• St Joseph's College, Geelong
• Trinity Grammar School, Kew
• Yeshivah College, Australia
• Xavier College

South Australia

• Blackfriars Priory School
• Christian Brothers College
• St Peter's College, Hackney
• St Paul's College, Adelaide
• Wesley College
• Prince Alfred College Kent Town
• Rostrevor College Woodforde
• North Adelaide Grammar School

Former boys' schools

• The Armidale School, NSW (Now co-educational)
• Macquarie Boys Technology High School
• Maryborough Boys' High School, merged into Maryborough State High School
• Newcastle Boys' High School, (now coeducational)
• Southwood Boys' Grammar School, merged into Tintern Grammar
• The School, Mount Victoria
• New Town High School, Tasmania (to become co-educational)
• Horton College Tasmania, closed in 1894
• Guildford Grammar School.(Now coeducational)
• St Patrick's College, Launceston, Tasmania (Now coeducational)
• Launceston Grammar School, Tasmania (Now coeducational)
• Scotch College, became Scotch Oakburn College (Tasmania)

Former

• Theresianum (now coeducational)

• Agdash Private Turkish High School

Former

• Baku Dede Gorgud Private Turkish High School (closed)
• Baku Private Turkish High School (closed)
• Sharur Turkish High School (closed)

• Chittagong Collegiate School
• Hazi Mohammad Mohsin Government High School

• Ma'had Islam Brunei
• Muda Hashim Secondary School
• Rimba Arabic Secondary School
• Sultan Omar Ali Saifuddien College

Note: Hassanal Bolkiah Boys' Arabic Secondary School, despite its name, admits both male and female students.

• St. George's School (Vancouver)
• Vancouver Christian School

• St. Andrew's College, Aurora

• Brebeuf College School
• Chaminade College School
• Neil McNeil High School
• St. Michael's College School
• Upper Canada College
• Royal St. George's College

Former:

• Michael Power High School, merged into Michael Power/St. Joseph High School
• De La Salle College (now coeducational)

• Selwyn House School

Former

• Collège Jean-de-Brébeuf (now coeducational)

Former

• American Academy of Larnaca (now coeducational)

• St Joseph's School, Addis Ababa

• Marist Brothers High School, Fiji
• Toorak Boys’ School

• Chavagnes International College

• Bayside Comprehensive School

• Fifth Boys Gymnasium of Thessaloniki (closed)

A non-profit public secondary school in the city of Thessaloniki's Analipsi neighborhood, comprised 3-year junior high school and 3-year high school (six-grade), and also Higher Education entrance education. Previous was the Villa Mehmet Kapandji, today is The Cultural Centre of Education Foundation of National Bank of Greece.

• Father Dueñas Memorial School

• Elizabeth College, Guernsey

• Benedictine High School of Pannonhalma
• Pelbart Temesvari Franciscan High School
• Piarist High School of Budapest

Please see, Category:Boys' schools in India.

Since the Iranian Revolution government schools have been divided by gender

• Tehran International School has separate campuses for boys.

Baghdad

• Baghdad College

Al Mutamayizeen Secondary has boys' schools.

• Alpha Boys School
• Cornwall College
• Jamaica College
• Munro College
• St. George's College

• De La Salle College, Jersey
• Victoria College, Jersey

• Alliance High School (Kenya)
• Highway Secondary School
• St. Mary's School, Nairobi
• Starehe Boys' Centre and School
• Maranda High School

• Kyunggi High School

Became coeducational

• American Boys College (now International College, Beirut)

Now coeducational

• Lycée de Garçons Esch-sur-Alzette (coeducational since 1969)
• Lycée de Garçons de Luxembourg (coeducational since the 1960s)

• English College Johore Bahru
• Methodist Boys' School, Kuala Lumpur
• Royal Military College
• Victoria Institution

• St. Edward's College, Malta
• St. Michael School (Malta)

• Ebène State Secondary School (Boys)^[1]
• Cosmopolitan College (Boys)
• Windsor College Boys

• Bachillerato Anáhuac Campus Monterrey

Irish Institute in the State of Mexico has a separate campus for boys.

Universidad Panamericana Preparatoria in Mexico City has a separate campus for boys.

Former boys schools

• St. Paul's College, Namibia, (now coeducational)

Former boys schools

• St. Xavier's School, Godavari (became coeducational in 1996)

Auckland Region

• Auckland Grammar School
• De La Salle College, Mangere East
• Dilworth School
• Kelston Boys' High School
• King's College, Auckland (Junior only)
• King's School, Auckland
• Liston College
• Rosmini College
• Sacred Heart College, Auckland
• Saint Kentigern Boys' School
• St Paul's College, Auckland
• St Peter's College, Auckland
• Westlake Boys High School
• Saint Kentigern College has gender separation in some classes
• St Stephens School (Tipene) (opening 2025)

Bay of Plenty Region

• Rotorua Boys' High School
• Tauranga Boys' College

Canterbury region

• Christchurch Boys' High School
• Christ's College, Christchurch
• Medbury School
• Shirley Boys' High School
• St Bede's College, Christchurch
• St Thomas of Canterbury College
• Timaru Boys' High School

Gisborne Region

• Gisborne Boys' High School

Hawke's Bay Region

• Hastings Boys' High School

• Lindisfarne College, New Zealand
• Napier Boys' High School
• St John's College, Hastings
• Te Aute College
• Te Aratika Academy

Manawatū-Whanganui

• Hato Paora College
• Palmerston North Boys' High School

Marlborough Region

• Marlborough Boys' College

Northland Region

• Whangarei Boys' High School

Otago region

• John McGlashan College
• King's High School, Dunedin
• Otago Boys' High School
• Waitaki Boys' High School

Southland region

• Southland Boys' High School

Taranaki Region

• Francis Douglas Memorial College
• New Plymouth Boys' High School

Tasman District

• Nelson College
• Nelson College Preparatory School

Waikato region

• Hamilton Boys' High School
• St John's College, Hamilton
• St Paul's Collegiate School (Junior only)

Wellington Region

• Hutt International Boys' School (Upper Hutt)
• St Bernard's College, Lower Hutt
• St Patrick's College, Kilbirnie, Wellington
• St Patrick's College, Silverstream
• Rathkeale College
• Rongotai College
• Wellesley College, New Zealand
• Wellington College, Wellington

Former boys' schools

• Hereworth School (coeducational since 2023)
• Waihi School (coeducational since 2021)
• Scots College, Wellington (coeducational since 2020)
• St Andrew's College, Christchurch (coeducation since 2001)

Abia State

• Government College Umuahia
• Marist Brothers' Juniorate, Uturu

Akwa Ibom State

• Holy Family College, Abak
• Methodist Boys' High School, Oron

Anambra State

• Bishop Crowther Seminary
• Christ the King College, Onitsha

Benue State

• St. Andrew's Secondary School, Adikpo^[2]

Delta State

• Government College Ughelli

Ebonyi State

• Government Secondary School, Afikpo

Imo State

• Government Secondary School, Owerri

Lagos State

• Eko Boys' High School
• Methodist Boys' High School, Lagos

Ogun State

• Baptist Boys' High School
• Ijebu Ode Grammar School
• King's College, Lagos
• Nigerian Navy Secondary School, Abeokuta

Oyo State

• Government College, Ibadan

Plateau State

• Air Force Military School, Jos, Nigeria

Government schools in this country are divided by gender

• Army Burn Hall College boys' campuses
• Islamabad College for Boys
• PAF College Lower Topa
• Sacred Heart High School for Boys

• Aquinas School
• Don Bosco Technical Institute of Makati
• Lourdes School of Mandaluyong
• PAREF Northfield School
• PAREF Southridge School
• PAREF Springdale School
• PAREF Westbridge School
• Xavier School

Government schools in this country are divided by gender

• Al-Thager Model School

All-boys secondary schools:

• Anglo-Chinese School (Barker Road)
• Anglo-Chinese School (Independent) (Secondary)
• Catholic High School (Secondary)
• Hwa Chong Institution (Secondary)
• Maris Stella High School (Secondary)
• Montfort Secondary School
• Raffles Institution (Secondary)
• St. Andrew's Secondary School
• St. Gabriel's Secondary School
• St. Joseph's Institution (Secondary)
• St. Patrick's School
• Victoria School

Eastern Cape

• Graeme College
• St Andrews College
• Grey High School
• Queen's College Boys' High School
• Dale College
• Selborne College
• Muir College

Free State

• Grey College
• St Andrew's School

Gauteng

• Parktown Boys' High School
• Pretoria Boys High School
• St Stithians College
• Springs Boys' High School
• King Edward VII School
• Christian Brothers' College, Boksburg
• Afrikaanse Hoër Seunskool
• St John's College
• St David's Marist, Inanda
• Jeppe High School for Boys
• St Benedict's College, Bedfordview
• St Alban's College
• St Declan's School for Boys
• Athlone Boys High School
• Highlands North Boys High School

KwaZulu-Natal

• Drakensberg Boys' Choir School
• St Charles College
• Kearsney College
• Michaelhouse
• Hilton College
• Clifton School
• Durban High School
• Northwood School
• Glenwood High School
• Maritzburg College
• Westville Boys High School
• Pinetown Boys' High School

Northern Cape

• Kimberley Boys' High School

North West

• Potchefstroom High School for Boys

Western Cape

• Hoër Landbouskool Boland
• Diocesan College
• Paarl Boys' High School
• Wynberg Boys' High School
• Rondebosch Boys High School
• Paul Roos Gymnasium
• South African College Schools
• Star College Bridgetown

• Taipei Municipal Jianguo High School

• Kibaha Secondary School

Now coeducational

• Lycée Saint-Joseph, Istanbul (became coeducational in 1987)

Moved

• American Boys College (now International College, Beirut) (was in İzmir/Smyrna, moved to Lebanon)

• Jinja College
• Namilyango College
• St. Mary's College Kisubi
• St. Henry's College Kitovu

Former boys' schools

• David Kaunda Technical High School (now coeducational)

• Kutama College (officially St Francis Xavier College)
• Peterhouse Boys' School

Adrianople Vilayet

• Bulgarian Men's High School of Adrianople

Aydin Vilayet

• American Boys College (now International College, Beirut) (Smyrna (now İzmir))

Constantinople Vilayet

• Lycée Saint-Joseph, Istanbul

Salonika Vilayet

• Bulgarian Men's High School of Thessaloniki (Salonika)

• Lists of girls' schools