Plechelm, O.S.B. (Plechelm of Guelderland, Plechelm, also Pleghelm or Plechelmus; died 730), is honored as a saint in both the Roman Catholic Church and the Old Catholic Church as a patron saint of the Netherlands.
Plechelm was an Irish Benedictine monk who traveled to Rome with two fellow monks, Saints Wiro and Otger. He became a missionary first in Northumbria, England, and then in the Kingdom of Frisia, now the Netherlands. He died in St. Odiliënberg.
Plechem was canonized by Pope Agapetus II about 950. As a result, the Basilica of St. Plechelm in Oldenzaal was built to enshrine his remains in 954.