Known as Division A from 48-49 thru 66-67; as Division AA from 67-68 thru 71-72. Became Division 3A with the formal creation of OFSAA in 72-73.
| YEAR | CHAMPION | COACH | FINAL | RUNNER-UP |
| 27-28 | Windsor-Walkerville Vocational | J.L. McNaughton | 38-24 | Ottawa Glebe |
| 28-29 | Windsor Assumption | John Higgins | T: 36-33 | Kingston Collegiate |
| 29-30 | Windsor Assumption | John Higgins | T:58-25 | Newmarket Pickering |
| 30-31 | Newmarket Pickering | T:85-49 | Niagara Falls Stamford | |
| 31-32 | Windsor-Walkerville Vocational | John Murray | (2-g1) | Niagara Falls Stamford |
| 32-33 | Windsor-Walkerville Vocational | John Murray | 33-17 | Hamilton Westdale |
| 33-34 | Toronto Humberside | C.S. Patterson | T:67-59 | Ottawa Glebe |
| 34-35 | Windsor Patterson | Ed Dawson | 37-29 | Ottawa Glebe |
| 35-36 | Windsor-Walkerville Vocational | Ian Allison | 35-20 | Ottawa Glebe |
| 36-37 | Windsor W.C. Kennedy | George Chapman | 44-17 | Hamilton Central |
| 37-38 | Windsor W.C. Kennedy | George Chapman | 24-23 | Ottawa Glebe |
| 38-39 | Windsor-Walkerville Vocational | Arnold Harrison | 29-23 | Ottawa Glebe |
| 39-40 | Windsor-Walkerville Vocational | Arnold Harrison | 33-30 | Ottawa Lisgar |
| 40-41 | Ottawa Lisgar | Harold Rothwell | 28-15 | London Central |
| 41-42 | Windsor Patterson | 41-22 | St. Catherine’s CI | |
| 42-43 | St. Catharines CI | Jim Weaver | 32-22 | Toronto Riverdale |
| 43-44 | St. Catharines CI | Jim Shaver | 34-29 | Toronto West End Y |
| 44-45 | Toronto Western Tech | Dalton White | 40-28 | Kitchener-Waterloo CI |
| 45-46 | Toronto East York | 39-33 | Toronto Oakwood | |
| 46-47 | Windsor Patterson | Joe Mencel | 47-46 | Toronto Runnymede |
| 47-48 | Windsor Patterson | Joe Mencel | 53-46 | Ottawa Glebe |
| 48-49 | Toronto East York | B. Miller | 41-37 | Sudbury Tech |
| 49-50 | Sault Ste. Marie CI | Tom Tipton | 54-35 | Niagara Falls CVI |
| 50-51 | Niagara Falls CVI | Jimmy Rose | 43-32 | Toronto Humberside College |
| 51-52 | Niagara Falls CVI | Jimmy Rose | 65-63 | Windsor Patterson CI |
| 52-53 | Niagara Falls CVI | Jimmy Rose | 62-44 | North Toronto Collegiate |
| 53-54 | Windsor Patterson | Joe Mencel | 65-59 | Niagara Falls C.V.I. |
| 54-55 | Niagara Falls Stamford CI | Johnny Lees | 54-47 | Windsor Patterson CI |
| 55-56 | Windsor Assumption | Father Matt Sheedy | 66-56 | London Sir Adam Beck CI |
| 56-57 | London Sir Adam Beck CI | Roger McCaulay | 67-35 | Toronto East York CI |
| 57-58 | Windsor Assumption | Father Matt Sheedy | 60-55 | Sudbury HS |
| 58-59 | Toronto Runnymede CI | Terry Housley | 52-45 | Sudbury HS |
| 59-60 | Toronto Runnymede CI | Terry Housley | 44-24 | Sudbury St. Charles |
| 60-61 | Windsor John L. Forster | Bill Burleigh | 56-46 | Ottawa Fisher Park HS |
| 61-62 | Niagara Falls CVI | Jimmy Rose | 62-38 | Niagara Falls District HS |
| 62-63 | Niagara Falls CVI | Jimmy Rose | 57-34 | Sudbury St. Charles |
| 63-64 | WEST: Niagara Falls CVI EAST: Brantford St. John’s | Jimmy Rose Brother Harvey Roach | 69-42 51-39 | Hamilton Hill Park SS Sudbury St. Charles |
| 64-65 | WEST: Hamilton Hill Park SS EAST: Sudbury Sheridan Tech | Bob Leedale Alex MacPherson | 43-40 57-54 | Windsor Walkerville Sault Ste. Marie Collegiate |
| 65-66 | WEST: Windsor Walkerville CI EAST: Ottawa Ridgemont HS | Fred Montour Bruce Campbell | 47-40 68-45 | Sault Ste. Marie Collegiate Oshawa Central CI |
| 66-67 | WEST: Windsor Assumption EAST: Peterborough Adam Scott | Jack Hool X | 45-39 46-34 | Hamilton Cathedral Oshawa Central CI |
| 67-68 | Hamilton Cathedral | Father Kyran Kennedy | 57-37 | Sudbury St. Charles |
| 68-69 | Windsor Assumption | Jack Hool | 60-35 | Brantford Pauline Johnson |
| 69-70 | Kitchener Forest Heights | Don McCrae | 67-61 | Tillsonburg Glendale |
| 70-71 | Burlington Nelson | John MacLennan | 58-56 | Kitchener Forest Heights |
| 71-72 | Windsor F.J. Brennan | Ron Innocente | 54-48 | Welland Notre Dame |
| 72-73 | Kitchener Eastwood | Hugh Heibein | 56-38 | Toronto George Harvey |
| 73-74 | Ottawa Lisgar | Larry Hale | 48-39 | Tillsonburg Glendale |
| 74-75 | Niagara Falls Stamford C.I. | Robert Coull | 60-51 | Sault Ste. Marie Bawating |
| 75-76 | Windsor W.D. Lowe SS | Gerry Brumpton | 66-53 | Tillsonburg Glendale |
| 76-77 | Windsor W.D. Lowe SS | Gerry Brumpton | 62-56 | Toronto Runnymede |
| 77-78 | St. Catharines Gov. Simcoe | Ken Walsh | 77-60 | Brantford St. John’s |
| 78-79 | Sarnia Central | John Thrasher | 54-49 | Windsor W.D. Lowe |
| 79-80 | Windsor W.F. Herman SS | Chris McCaffrey | 77-68 | Toronto Oakwood |
| 80-81 | Windsor W.F. Herman SS | Chris McCaffrey | 54-52 | Windsor W.D. Lowe |
| 81-82 | Toronto Eastern Commerce | Ernie Armstrong | 76-61 | Windsor W.D. Lowe |
| 82-83 | Kitchener Cameron Heights | Court Heinbuch | 44-42 | Windsor W.F. Herman |
| 83-84 | Hamilton Cathedral | Mark Walton | 57-53 | Toronto Runnymede |
| 84-85 | Toronto Runnymede | John Petruschak | 59-55 | Toronto Eastern Commerce |
| 85-86 | Toronto Runnymede | John Petruschak | 58-56 | Niagara Falls Stamford |
| 86-87 | Kitchener St. Jerome’s | Tom Kieswetter | 53-51 | Agincourt Stephen Leacock CI |
| 87-88 | North York Bathurst Heights | Bob Maydo | 72-55 | St. Catharines Governor Simcoe |
| 88-89 | Toronto Runnymede | John Petruschak | 80-64 | Ottawa Sir Robert Borden |
| 89-90 | Toronto Runnymede | John Petruschak | 68-66 | Toronto Oakwood CI |
| 90-91 | Hamilton St. Mary’s | Joe Raso | 73-70 | Windsor W.D. Lowe |
| 91-92 | Oshawa O’Neill | Craig Andrews | 64-56 | Toronto Runnymede |
| 92-93 | Toronto Oakwood | Terry Thomson | 58-36 | Brantford St. John’s |
| 93-94 | Hamilton Cathedral | Mark Walton | 54-29 | Ottawa Sir Robert Borden |
| 94-95 | Toronto Eastern Commerce | Simeon Mars | 49-47 | Mississauga Westwood |
| 95-96 | Toronto Eastern Commerce | Simeon Mars | 65-54 | Toronto Runnymede |
| 96-97 | Scarborough Dr. Norman Bethune | Bob Selkirk | 67-42 | Toronto Oakwood |
| 97-98 | Hamilton Cathedral | Mark Walton | 50-49 | Toronto Eastern Commerce |
| 98-99 | Guelph St. James | Bob Sharp | 83-59 | Hamilton Cathedral |
| 99-00 | North York Bathurst Heights | Bob Maydo | 73-43 | Ottawa St. Patrick’s |
| 00-01 | Burlington Nelson | Bob Stacey | 54-45 | Burlington Notre Dame |
| 01-02 | Toronto Central Commerce | Larry Laughlin | 64-55 | Dundas Highland |
| 02-03 | Kingston Frontenac | Suche James | 58-49 | Toronto Central Commerce |
| 03-04 | Toronto Emery | Bob Maydo | 48-46 | Sarnia St. Claire |
| 04-05 | Sarnia St. Patrick’s | Adam Aquilina | 68-63 | Toronto Emery |
| 05-06 | Windsor Catholic Central | Pete Cusumano | 69-66 | Toronto Vaughan Road |
| 06-07 | Cambridge Southwood | Rob Baird | 39-37 | Windsor Catholic Central |
| 07-08 | Ottawa St. Patrick | Mike Rowley | 63-62 | Thornhill Vaughan |
| 08-09 | Ottawa St. Matthew | Jason Wren/Will Hinz | 57-47 | Toronto Emery |
| 09-10 | Etobicoke Martingrove | Shawn Gray | 56-54 | Oakville St. Ignatius of Loyola |
| 10-11 | Whitby Anderson | Dean Hutchcroft | 69-64 | Newmarket Dr. John M. Denison |
| 11-12 | Whitby Anderson | Dean Hutchcroft | 62-60 | Burlington Notre Dame |
| 12-13 | Windsor Catholic Central | Pete Cusumano | 75-51 | Ottawa St. Patrick |
| 13-14 | Stoney Creek Saltfleet | Dave Ormerod | 54-50 | Windsor Catholic Central |
| 14-15 | Windsor Catholic Central | Pete Cusumano | 66-58 | Toronto West Humber |
| 15-16 | Etobicoke Father Henry Carr | Paul Melnik | 61-53 | Toronto Oakwood |
| 16-17 | Toronto St. Michael’s | Jeff Zownir | 71-90 | Cambridge St. Benedict |
| 17-18 | Pickering Pine Ridge | Cameron Nekkers | 76-72 | Mississauga St. Francis Xavier |
| 18-19 | Pickering Pine Ridge | Cameron Nekkers | 51-48 | Kingston LaSalle |
| 19-20 | North York Crestwood | Ro Russell | 79-55 | Windsor W.C. Kennedy |
| 20-21 | CANCELLED | (covid-19 pandemic) | —– | ——————————— |
| 21-22 | CANCELLED | (covid-19 pandemic) | —– | ——————————— |
| 22-23 | Toronto Oakwood | Anthony Miller | 69-51 | Chatham Ursuline |
| 23-24 | Toronto Oakwood | Anthony Miller | 53-38 | Stoney Creek Saltfleet |