Atom Champions
| YEAR | A | B | C |
| 1951-52 | ROCKY RIVER CONSTRUCTION | ||
| 1952-53 | WOODVIEW PARK | ||
| 1953-54 | NO SERIES | ||
| 1954-55 | METAL ART RAIL | ||
| 1955-56 | ROBINSON GENERALS | ||
| 1956-57 | HUMBER VALLEY | ||
| 1957-58 | AGINCOURT ADMIRALS | ||
| 1958-59 | FIAT 600’S | ||
| 1959-60 | CLIFFCREST JETS | ||
| 1960-61 | PEACOCK FLOORING | ||
| 1961-62 | NORTH YORK KNIGHTS | ||
| 1962-63 | DON MILLS CIVITAN | ||
| 1963-64 | EASTERN FREIGHTWAYS | ||
| 1964-65 | BLUE LINE SKATE LACES | ||
| 1965-66 | CHRISTIES COOKIES | BLUE LINE SKATE LACES | |
| 1966-67 | GEORGE BELL | SCARBORO OLYMPIC | |
| 1967-68 | SCOTTS COLONELS | HORTON SPICE MILLS | |
| 1968-69 | MARLBOROS HC | RAY MASONRY | |
| 1969-70 | TORONTO OLYMPIC | NORTHERN ETOBICOKE | TED REEVE |
| 1970-71 | DORSET PARK | WILLOWDALE | WEST HILL |
| YEAR | AA | A | B |
| 1971-72 | DON VALLEY | YORK MILLS | TED REEVE |
| 1972-73 | DON VALLEY | CEDAR HILL | CLARKSON |
| 1973-74 | NO RECORD | NO RECORD | NO RECORD |
| 1974-75 | MISSISSAUGA REPS | WEXFORD | AGINCOURT |
| 1975-76 | DORSET PARK | AGINCOURT | GOULDING PARK |
| 1976-77 | NO RECORD | NO RECORD | NO RECORD |
| 1977-78 | MARLBOROS HC | MISSISSAUGA REPS | EAST YORK |
| YEAR | MAJOR | AA | A |
| 1978-79 | NORTH YORK FLAMES | ETOBICOKE REPS | EAST YORK |
| 1979-80 | YOUNG NATS | METRO BLACKHAWKS | TED REEVE |
| 1980-81 | MARLBOROS HC | NORTH TORONTO | EAST YORK |
| 1981-82 | MISSISSAUGA REPS | HILLCREST | WEST TORONTO PIRATES |
| 1982-83 | YOUNG NATS | MISSISSAUGA N-STARS | THORNHILL ISLANDERS |
| 1983-84 | MARLBOROS HC | MISSISSAUGA JETS | ROYAL YORK RANGERS |
| 1984-85 | YOUNG NATS | GOULDING PARK | HUMBER VALLEY |
| 1985-86 | MARLBOROS HC | NORTH TORONTO | ROYAL YORK RANGERS |
| 1986-87 | TORONTO RED WINGS | GOULDING PARK | ST BENEDICTS |
| 1987-88 | METRO BLACKHAWKS | MISSISSAUGA BRAVES | HUMBERVIEW |
| 1988-89 | MISSISSAUGA REPS | HILLCREST SUMMITS | EAST ENDERS |
| 1989-90 | WEXFORD | MISSISSAUGA TERRIERS | EAST ENDERS |
| 1990-91 | TORONTO RED WINGS | YORK TOROS | WEST MALL WOLVES |
| 1991-92 | TORONTO RED WINGS | HILLCREST | WARREN PARK |
| 1992-93 | WEXFORD | MISSISSAUGA BRAVES | ROYALS |
| 1993-94 | TORONTO RED WINGS | NORTH TORONTO | WILLOWDALE |
| 1994-95 | NO RECORD | NO RECORD | NO RECORD |
| 1995-96 | MARLBOROS HC | NORTH TORONTO | HUMBERVIEW |
| 1996-97 | NORTH YORK CANADIENS | MISSISSAUGA BRAVES | VAUGHAN PANTHERS |
| 1997-98 | NO RECORD | NO RECORD | NO RECORD |
| 1998-99 | NORTH YORK RANGERS | NORTH TORONTO | VAUGHAN PANTHERS |
| 1999-2000 | NORTH YORK CANADIENS | MISSISSAUGA TERRIERS | NORTH YORK KNIGHTS |
| 2000-01 | TORONTO RED WINGS | SCARBORO BRUINS | DOWNSVIEW BEAVERS |
| YEAR | AAA | AA | A |
| 2001-02 | MISSISSAUGA REBELS | MISSISSAUGA BRAVES | VAUGHAN RANGERS |
| 2002-03 | TORONTO JR. CANADIENS | HUMBER VALLEY SHARKS | VAUGHAN RANGERS |
| 2003-04 | MARLBOROS HC | MISSISSAUGA TERRIERS | WILLOWDALE BLACKHAWKS |
| 2004-05 | MARLBOROS HC | HUMBER VALLEY SHARKS | HUMBER VALLEY SHARKS |
| 2005-06 | TORONTO RED WINGS | NORTH TORONTO | LEASIDE FLAMES |
| 2006-07 | MARLBOROS HC | MISSISSAUGA BRAVES | TED REEVE THUNDER |
| 2007-08 | MARLBOROS HC | WEST MALL LIGHTNING | HUMBERVIEW HUSKIES |
| 2008-09 | MARLBOROS HC | MISSISSAUGA JETS | NORTH TORONTO |
| 2009-10 | VAUGHAN KINGS | MARKHAM ISLANDERS | TORONTO ACES |
| 2010-11 | MISSISSAUGA REBELS | STREETSVILLE TIGERS | VAUGHAN PANTHERS |
| 2011-12 | MISSISSAUGA REPS | NORTH YORK KNIGHTS | LEASIDE FLAMES |
| 2012-13 | TORONTO JR. CANADIENS | WEST HILL GOLDEN HAWKS | LEASIDE FLAMES |
| 2013-14 | TORONTO MARLBOROS | NORTH TORONTO | VAUGHAN RANGERS |
| 2014-15 | TORONTO JR. CANADIENS | TED REEVE THUNDER | MARKHAM ISLANDERS |
| 2015-16 | VAUGHAN PANTHERS | VAUGHAN RANGERS | TORONTO MARLBOROS |
| 2016-17 | NORTH TORONTO | NORTH TORONTO | MISSISSAUGA SENATORS |
