The Tree Register, or more fully, the Tree Register of the British Isles (T.R.O.B.I.), is a registered charity run by volunteers, collating and updating a database of notable trees throughout Britain and Ireland. It comprises a computer database which in 2022 contained details of 250,000 trees. It was established in 1988 by co-founders Vicky Hallett, who later became Vicky Schilling, and Alan Mitchell, the internationally acclaimed dendrologist.