Local Chapters of ATOS are the organizations that really do all the work of preserving and presenting Theatre Organ to the public. Please lookup the Chapters in your area and get involved!
| Chapter | State/Prov. | City |
|---|---|---|
| Alabama | Alabama | Birmingham |
| Atlanta | Georgia | Atlanta |
| Australia Felix | Australia-Wide | |
| Binghamton Theatre Organ Society, Inc. | New York | Binghamton |
| Bluegrass | Kentucky | Lexington |
| Cedar Rapids | Iowa | Cedar Rapids |
| Central Florida | Florida | |
| Central Indiana | Indiana | Indianapolis |
| Chicago Area | Illinois | Chicago |
| Chicagoland | Illinois | Chicago |
| Cinema Organ Society (affiliate) | United Kingdom | |
| Columbia River | Washington | Vancouver |
| Connecticut Valley | Connecticut | |
| Cumberland Valley | Pennsylvania | Chambersburg |
| Dairyland | Wisconsin | Milwaukee |
| Delaware Valley | Pennsylvania | |
| Detroit Theatre Organ Society (affiliate) | Michigan | Detroit |
| Dickinson Theatre Organ Society | Delaware | Wilmington |
| EASTERN MASSACHUSETTES | Massachusetts | |
| Free State | Maryland | Catonsville |
| Garden State | New Jersey | Jersey City |
| Great Lakes Bay | Michigan | Saginaw |
| GREAT SALT LAKE | Utah | Salt Lake City |
| Houston | Texas | Houston |
| Hudson Mohawk | New York | Schenectady |
| JESSE CRAWFORD | Montana | Billings |
| Joliet Area | Illinois | Joliet |
| Kansas City | Missouri | Kansas City |
| Kingston | Canada | Kingston |
| LA CROSSE SCENIC BLUFFS | Wisconsin | |
| Land O' Lakes | Minnesota | Minneapolis / St. Paul |
| Lansing Theatre Organ, Inc. (affiliate) | Michigan | Lansing |
| London and South of London | England, General | London |
| Los Angeles | California | Los Angeles |
| MAGNOLIA | Mississippi | |
| Manasota | Florida | Sarasota |
| Motor City | Michigan | Detroit |
| New York | New York | New York City |
| NorCal | California | San Francisco |
| North Texas | Texas | Dallas / Ft. Worth |
| NORTHERN MICHIGAN | Michigan | Traverse City |
| Ohio Valley | Ohio | Cincinnati |
| Old Dominion | Virginia | Richmond |
| Orange County | California | Fullerton |
| Packerland | Wisconsin | |
| Piedmont | North Carolina | Burlington |
| Pikes Peak | Colorado | Colorado Springs |
| Pine Tree | Maine | Old Orchard Beach |
| Pittsburgh Area Theatre Organ Society (Affiliate) | Pennsylvania | Pittsburgh |
| Puget Sound | Washington | Seattle |
| Red River Theatre Organ Society | North Dakota | Fargo |
| River City | Nebraska | Omaha |
| Rochester Theatre Organ Society (affiliate) | New York | Rochester |
| Rocky Mountain | Colorado | Denver |
| Saint Louis | Missouri | St. Loius |
| San Diego | California | San Diego |
| Santa Barbara | California | Santa Barbara |
| Sierra | California | Sacramento |
| Sooner State | Oklahoma | Tulsa |
| South Florida | Florida | |
| Spokane First Nazarene | Washington | Spokane |
| Susquehanna Valley | Pennsylvania | York |
| Valley of the Sun | Arizona | Phoenix |
| Western Reserve | Ohio | Cleveland |