Sir Thaddeus Pearcey McCarthy ONZ KBE (24 August 1907 – 11 April 2001) was a New Zealand jurist.
McCarthy was educated at St Bede's College, Christchurch, and then studied law at Victoria University College, New Zealand and graduated in 1928.
He practised at the Wellington bar for 26 years until his appointment to the bench.
McCarthy was in active service overseas during the Second World War.
McCarthy had a reputation as a "plain English" judge with an outstanding ability to make complex matters understandable.