Here is a general ranking of some of Ontario's native tree species by height, from tallest to shortest. The heights are approximate and can vary based on growing conditions and age.

Tallest to Shortest Ontario Tree Species
1. Eastern White Pine (Pinus strobus)
Height: Up to 30-40m (100-130ft)
Ontairo's provincial tree and often the tallest native tree in the region.
2. Red Pine (Pinus resinosa)
Height: Up to 20-35m (65-115ft)
3. Eastern Hemlock (Tsuga Canadensis)
Height: Up to 20-30m (65-100ft)
4. Sugar Maple (Acer saccharum)
Height: Up to 20-27m (65-90ft)
5. American Beech (Fagus grandifolia)
Height: Up to 20-25m (65-80ft)
6. Red Maple (Acer rubrum)
Height: Up to 15-25m (50-80ft)
7. Bur Oak (Quercus macrocarpa)
Height: Up to 15-25m (50-80ft)
8. White Spruce (Picea glauca)
Height: Up to 15-20m (50-65ft)
9. Paper Birch (Betula papyrifera)
Height: Up to 12-20m (40-65ft)
10. Tamarack (Eastern Larch) (Larix laricina)
Height: Up to 10-20m (30-65ft)
11. Black Cherry (Prunus serotina)
Height: Up to 10-15m (30-50ft)
12. Eastern Red Cedar (Juniperus virginiana)
Height: Up to 10-15 (30-50ft)
13. Americam Mountain Ash (Sorbus Americana)
Height: Up to 6-12m (20-40ft)
14. Staghorn Sumac (Rhus typhina)
Height: Up to 3-6m (10-20ft)

Some notable species for their trunk diameter:

Trees with Large Diameters in Ontario
1. Eastern White Pine (Pinus strobus)
Diameter: Can reach up to 1.5-2m (5-6.5ft).
Age for Max Size: 150-200yrs or more. These iconic trees are slow growing and can live for several centuries in ideal conditions.
2. American Elm (Ulmus americana)
Diameter: Up to 1.5m (5ft) though many have been lost due to Dutch elm disease.
Age for Max Size: Around 100-150yrs for maximum growth.
3. Sugar Maple (Acer saccharum)
Diameter: Can grow to 1.2-1.5m (4-5ft).
Age for Max Size: Approximately 200-300yrs in undisturbed areas.
4. Eastern Hemlock (Tsuga canadensis)
Diameter: Reaches up to 1.2m (4ft) in old-growth forests.
Age for Max Size: 300-400yrs or more. Eastern Hemlocks are among the oldest living trees in Ontario.
5. Red Oak (Quercus rubra)
Diameter: Can grow to 1.2m (4ft).
Age for Max Size: Around 200-250yrs.
6. White Oak (Quercus alba)
Diameter: Can reach up to 1.5m (5ft)
Age for Max Size: 300-400yrs or more. White Oaks are highly long-lived and can grow exceptionally wide over time.
7. Bur Oak (Quercus macrocarpa)
Diameter: Often reaches 1.5m (5ft), with exceptional specimens surpassing this.
Age for Max Size: 200-400yrs. Known for its thick trunk and wide spread, it thrives in both wet and dry conditions.
8. Black Walnut (Juglans nigra)
Diameter: Can grow to 1.2m (4ft)
Age for Max Size: 150-250yrs. Its valuable hardwood makes it a prized species.
9. White Ash (Fraxinus americana)
Diameter: Up to 1m (3-4ft).
Age for Max Size: 150-200yrs. Many older trees have been affected by the emerald ash borer.
10. Eastern Cottonwood (Populus deltoides)
Diameter: Can grow to 2m (6.5ft) or more.
Age for Max Size: Around 70-100yrs. Known for rapid growth, these trees reach large diameters relatively quickly compared to others.

Notable Large Trees in Ontario
The "Cheesewring Tree" (an Eastern White Pine) in Algonquin Park is one of Ontarios largest trees, estimated to be over 500yrs old with an impressive diameter.
A Bur Oak in Hamilton has a trunk diameter exceeding 1.8m (6ft) and is estimated to be over 300yrs old.