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