Sectional and Super-Sectional hosts are listed further down this page.

1999-2000 Class A Boys Basketball Regional Sites
Altamont
Anna (A.-Jonesboro)
Arthur
Auburn
Bement
Breese (Central)
Brimfield
Byron
Cairo
Carlinville
Casey (C.-Westfield)
Chicago (Hales Franciscan)
Chicago (St. Benedict)
Chicago (St. Francis de Sales)
Dallas City
Danville (Schlarman)
DuQuoin
Edinburg
Effingham (St. Anthony)
El Paso
Elmhurst (Immaculate Conception)
Elmhurst (Timothy Christian)
Flora
Freeburg
Fulton (H.S.)
Genoa (G.-Kingston)
Gibson City (G.C.-Melvin-Sibley)
Gilman (Iroquois West)
Hampshire
Hardin (Calhoun)
Harrisburg
Herscher
Hoopeston (H. Area)
Jacksonville (Routt)
Johnston City
Joy (Westmer)
Kewanee (H.S.)
Knoxville
LeRoy
Lewistown
Litchfield
Manteno
Mason City (Illini Central)
McLeansboro
Monmouth (H.S.)
Mt. Sterling (Brown County)
Newton
Normal (University)
Ottawa (Marquette)
Payson (Seymour)
Pearl City
Port Byron (Riverdale)
Riverton
Roxana
Sandwich
Shabbona (Indian Creek)
Shelbyville
Somonauk
South Beloit
Spring Valley (Hall)
Tuscola
Warren
Waterloo (Gibault)
Woodlawn

1999-2000 Class A Boys Basketball Sectional Sites
Braidwood (Reed Custer)
Bridgeport (Red Hill)
Chillicothe (Illinois Valley Central)
Fairbury (Prairie Central)
Maple Park (Kaneland)
Mendota
Metropolis (Massac County)
Orion
Petersburg (PORTA)
Pinckneyville
Quincy (Notre Dame)
Rock Falls
St. Joseph (S.J.-Ogden)
Warrensburg (W.-Latham)
Westmont
Wood River (East Alton-W.R.)

1999-2000 Class A Boys Basketball Super-Sectional Sites
Southern Illinois University, Carbondale
Eastern Illinois University, Charleston
Northern Illinois University, DeKalb
Millikan University, Decatur
East Moline (United)
Olivet Nazarene University, Kankakee
Western Illinois University, Macomb
Illinois State University, Normal