This is a list of high schools in the state of Montana.

The Montana High School Association is the governing body of high school athletics. Schools are assigned a class to determine athletic competitions. As of 2023, the enrollment criteria for each class is: 801 and up for Class AA, 301-800 for Class A, 101-300 for Class B and 1-100 for Class C.^[1]

• Beaverhead County High School, Dillon, Class A
• Lima High School, Lima, Class C

• Hardin High School, Hardin, Class A
• Lodge Grass High School, Lodge Grass, Class B
• Northern Cheyenne High School, Busby, Class C
• Northern Cheyenne Tribal School, Busby (Non Affiliated with MHSA - no classification)
• Plenty Coups High School, Pryor, Class C

• Chinook High School, Chinook, Class B
• Harlem High School, Harlem, Class B
• Hays-Lodge Pole High School, Hays, Class C
• Turner High School, Turner, Class C

• Broadwater High School, Townsend, Class B

• Belfry High School, Belfry, Class C
• Bridger High School, Bridger, Class C
• Fromberg High School, Fromberg, Class C
• Joliet High School, Joliet, Class B
• Red Lodge High School, Red Lodge, Class B
• Roberts High School, Roberts, Class C

• Carter County High School, Ekalaka, Class C

• Belt High School, Belt, Class C
• Cascade High School, Cascade, Class C
• Centerville High School, Centerville, Class C
• Charles M. Russell High School (CMR), Great Falls, Class AA
• Great Falls Central Catholic High School, Great Falls, Class B
• Great Falls High School, Great Falls, Class AA
• Montana School for Deaf & Blind High, Great Falls, Class C
• Simms High School, Simms, Class C

• Big Sandy High School, Big Sandy, Class C
• Fort Benton High School, Fort Benton, Class C
• Geraldine High School, Geraldine, Class C
• Highwood High School, Highwood, Class C

• Custer County High School, Miles City, Class A

• Scobey High School, Scobey, Class C

• Dawson High School, Glendive, Class A
• Richey High School, Richey, Class C

• Anaconda High School, Anaconda, Class B

• Baker High School, Baker, Class B
• Plevna High School, Plevna, Class C

• Denton High School, Denton, Class C
• Fergus County High School, Lewistown, Class A
• Grass Range High School, Grass Range, Class C
• Moore High School, Moore, Class C
• Roy High School, Roy, Class C
• Winifred High School, Winifred, Class C

• Bigfork High School, Bigfork, Class A
• Columbia Falls High School, Columbia Falls, Class A
• Flathead High School, Kalispell, Class AA
• Glacier High School, Kalispell, Class AA
• Stillwater Christian School, Kalispell, [Non Affiliated with MHSA - no classification]
• Whitefish High School, Whitefish, Class A

• Belgrade High School, Belgrade, Class AA
• Bozeman High School, Bozeman, Class AA
• Gallatin High School, Bozeman, Class AA
• Heritage Christian School, Bozeman [Non affiliated with MHSA - no classification]
• Lone Peak High School, Big Sky, Montana, Class B
• Manhattan Christian School, Churchill, Class C
• Manhattan High School, Manhattan, Class B
• Mount Ellis Academy, Bozeman, [Non affiliated with MHSA - no classification]
• Three Forks High School, Three Forks, Class B
• West Yellowstone High School, West Yellowstone, Class C
• Willow Creek High School, Willow Creek, Class C

• Garfield County District High School, Jordan, Class C

• Browning High School, Browning, Class A
• Cut Bank High School, Cut Bank, Class B

• Lavina High School, Lavina, Class C
• Ryegate High School, Ryegate, Class C

• Drummond High School, Drummond, Class C
• Granite High School, Philipsburg, Class C

• Box Elder High School, Box Elder, Class C
• Rocky Boy High School, Box Elder, Class B
• Havre High School, Havre, Class A
• North Star High School, Rudyard, Class C

• Jefferson High School, Boulder, Class B
• Whitehall High School, Whitehall, Class B

• Geyser High School, Geyser, Class C
• Hobson High School, Hobson, Class C
• Stanford High School, Stanford, Class C

• Arlee High School, Arlee, Class B
• Charlo High School, Charlo, Class C
• Two Eagle River School, Pablo, Class C
• Polson High School, Polson, Class A
• Ronan High School, Ronan, Class A
• Mission High School, St. Ignatius, Class B

• Augusta High School, Augusta, Class C
• Capital High School, Helena, Class AA
• East Helena High School, East Helena, Class A
• Helena High School, Helena, Class AA
• Lincoln High School, Lincoln, Class C

• Chester-Joplin-Inverness High School (CJI), Chester, Class C

• Lincoln County High School, Eureka, Class B
• Libby High School, Libby, Class A
• Troy High School, Troy, Class C

• Ennis High School, Ennis, Class B
• Harrison High School, Harrison, Class C
• Sheridan High School, Sheridan, Class C
• Twin Bridges High School, Twin Bridges, Class C

• Circle High School, Circle, Class C

• White Sulphur Springs High School, White Sulphur Springs, Class C

• Alberton High School, Alberton, Class C
• St. Regis High School, St. Regis, Class C
• Superior High School, Superior, Class C

• Big Sky High School, Missoula, Class AA
• Frenchtown High School, Frenchtown, Class A
• Hellgate High School, Missoula, Class AA
• Loyola Sacred Heart High School, Missoula, Class B
• Missoula International School, Missoula
• Seeley-Swan High School, Seeley Lake, Class C
• Sentinel High School, Missoula, Class AA
• Valley Christian School, Missoula, Class C
• Willard Alternative High School, Missoula

• Melstone High School, Melstone, Class C
• Roundup High School, Roundup, Class B

• Gardiner High School, Gardiner, Class C
• Park High School, Livingston, Class A
• Shields Valley High School, Clyde Park, Class C

• Winnett High School, Winnett, Class C

• Dodson High School, Dodson, Class C
• Malta High School, Malta, Class B
• Saco High School, Saco, Class C
• Whitewater High School, Whitewater, Class C

• Conrad High School, Conrad, Class B
• Heart Butte High School, Heart Butte, Class C
• Valier High School, Valier, Class C

• Powder River County District High School, Broadus, Class C

• Powell County High School, Deer Lodge, Class B

• Terry High School, Terry, Class C

• Corvallis High School, Corvallis, Class A
• Darby High School, Darby, Class C
• Florence-Carlton High School, Florence, Class B
• Hamilton High School, Hamilton, Class A
• Stevensville High School, Stevensville, Class A
• Victor High School, Victor, Class C

• Fairview High School, Fairview, Class C
• Lambert High School, Lambert, Class C
• Savage High School, Savage, Class C
• Sidney High School, Sidney, Class A

• Bainville High School, Bainville, Class C
• Brockton High School, Brockton, Class C
• Culbertson High School, Culbertson, Class C
• Froid High School, Froid, Class C
• Poplar High School, Poplar, Class B
• Wolf Point High School, Wolf Point, Class B

• Colstrip High School, Colstrip, Class B
• Forsyth High School, Forsyth, Class C
• Lame Deer High School, Lame Deer, Class B
• Rosebud High School, Rosebud, Class C
• St. Labre Indian Catholic High School, Ashland, Class B

• Hot Springs High School, Hot Springs, Class C
• Noxon High School, Noxon, Class C
• Plains High School, Plains, Class C
• Thompson Falls High School, Thompson Falls, Class B

• Medicine Lake High School, Medicine Lake, Class C
• Plentywood High School, Plentywood, Class C
• Westby High School, Westby, Class C

• Butte Central Catholic High School, Butte, Class A
• Butte High School, Butte, Class AA

• Absarokee High School, Absarokee, Class C
• Columbus High School, Columbus, Class B
• Park City High School, Park City, Class C
• Rapelje High School, Rapelje, Class C
• Reed Point High School, Reed Point, Class C

• Sweet Grass County High School, Big Timber, Class B

• Choteau High School, Choteau, Class B
• Dutton/Brady High School, Dutton, Class C
• Fairfield High School, Fairfield, Class B
• Power High School, Power, Class C

• North Toole County High School, Sunburst, Class C
• Shelby High School, Shelby, Class B

• Hysham High School, Hysham, Class C

• Frazer High School, Frazer, Class C
• Lustre Christian High School, Lustre, Class C
• Glasgow High School, Glasgow, Class B
• Hinsdale High School, Hinsdale, Class C
• Nashua High School, Nashua, Class C
• Opheim High School, Opheim, Class C

• Harlowton High School, Harlowton, Class C
• Judith Gap High School, Judith Gap, Class C

• Wibaux High School, Wibaux, Class C

• Billings Central Catholic High School, Billings, Class A
• Billings Senior High School, Billings, Class AA
• Billings West High School, Billings, Class AA
• Broadview High School, Broadview, Class C
• Custer High School, Custer, Class C
• Huntley Project High School, Worden, Class B
• Laurel High School, Laurel, Class A
• Lockwood High School, Lockwood, Class A
• Rimrock Christian High School, Billings, [Non affiliated with MHSA - no classification]
• Shepherd High School, Shepherd, Class B
• Skyview High School, Billings, Class AA
• Yellowstone Academy, Billings, [Non affiliated with MHSA - no classification]

• List of high schools in Montana from SchoolTree.org
• https://web.archive.org/web/20110521095619/http://mhsa.org/Enrollment/2010-11FallEnrollmentByClassification.pdf