Tytsjerksteradiel (Dutch: Tietjerksteradeel) is a municipality in the province of Friesland in the Netherlands. It is named after the town of Tytsjerk, whose name is derived from a person named Tiete. Tiete was a daughter of Tryn, after whom the region (Trynwâlden) is named. The other villages in Trynwâlden are also named after Tryn's children: Oentsjerk (Oene), Gytsjerk (Giete), Readtsjerk (Reade), Aldtsjerk (Âlde), Ryptsjerk (Rype). A statue of Tryn and her children is placed in Oentsjerk next to the mainroad (Rengerswei). Tsjerk is the West Frisian word for Church. Until 1989 the official name of the municipality was Tietjerksteradeel (), the Dutch name; the current official name is West Frisian. The largest village in the municipality is Burgum.