Well the tallest is cherrybark oak at over 160 feet....

According to the National Register of Big Trees (so these are all US records), the top few Quercus species are:

Quercus chrysolepis (canyon live oak) in Oak Glen county, CA: 621 points
Quercus virginiana (live oak) in St. Tammany Parish, LA: 570 points
Quercus lobata (valley oak) in Mendocino county, CA: 526 points
Quercus falcata (southern red oak) in Upton county, GA: 508 points
Quercus pagoda (cherrybark oak) in Tipton county, TN: 486 points

The Wye oak (Q alba) on the MD eastern shore, now deceased, would've been right up there. It was over 10' in dia at breast height, and far bigger at the root butress.

The English oak may be the largest....there are some in Poland that are freakishly large in bialowezia forest..it's a large virgin forest

The English oak may be the largest....there are some in Poland that are freakishly large in bialowezia forest..it's a large virgin forest

According to wikipedia the tallest english oak in Bialowieza is 46m/150 feet, it is in the belarussian side of the forest and not the polish side though. Pretty impressing but still not as tall as that 160 feet cherrybark oak

Thanks everyone... I didn't know Q. chrysolepsis grew that big.... and Q. pagoda that tall. I've seen pics of the Wye oak before, very impressive tree indeed.
I've never heard of those large oaks at the BiaÃÂowieüa forest before. I just googled them. It should be a good idea to take a trip there.. not only for the oak, but to see those bison as well.
Any large oak species in Asia?

Quercus Robur in Europe have been recorded as being really ancient and super humongous. If we would have planted it here centuries ago we would be able to judge it fairly.

Yes, a quercus robur left alone in the Appalachians for a few hundred years might actually be larger than those in Bialowieza today. After all that is not the most favorable place in Europe when it comes to climate. A hilly place in France might be better, but those places has been disturbed by human activity for thousands of years. But I still don't know if q. robur would grow larger than the american species. Or the asian species, we do not know very much about those here in the western world

Its hard to determine the genetic potential of each species since humans seem to get a high from cutting down the largest trees they come across. Early American explorers often mention trees that were much larger and taller than those back in Europe. However the exact sizes and species were rarely recorded. I did come across one record though of an eastern white pine that was 230 feet tall....you won't find one that big anymore. So I think the American oaks may have achieved a much greater stature than they do today...its just that all the largest ones were cut and never documented.

True.. plus it seems to me that oaks tend to grow in more accessible places than some conifers... making them easy targets for loggers