Chris Clues, tree and woodland manager at Cragside, said: "It is a truly wonderful specimen - not like other commercially grown Scots pine trees, which are usually grown and thinned out after 30 years. This one has been left to its own devices and has a deep bushy crown to it."
It is the estate's fifth "champion tree" - recorded as being the tallest or widest of its kind in the county or the UK.
Experts from charity the Tree Register of the British Isles visit the trees to climb and measure them before officially recognising their status, and the Cragside pine is the 200,000th tree to join the register.
Brian Muelaner, ancient tree adviser for the National Trust, said: "This is a surprising result as you'd think the tallest Scots pine in the UK would be found in Scotland.
"This exciting new record adds to the 200 champion trees already found on Trust land."