Stithians (Cornish: Stedhyans), also known as St Stythians, is a town and civil parish in Cornwall, England, United Kingdom. It lies in the middle of the triangle bounded by Redruth, Helston and Falmouth. Its population (2001) is 2,004, increasing to 2,101 at the 2011 census An electoral ward in the same name also exists but stretches north to St Day. The population here also at the 2011 census was 5,023.
The parish is mainly agricultural, lying south of the Gwennap mining area and north of the quarrying areas of Rame and Longdowns. The River Kennall runs through the parish: in the 19th century, this river worked a flour mill and a number of gunpowder mills, machinery at a foundry, and a paper mill.
The parish church is dedicated to St Stythian, but it is hard to identify this saint. References to the parish in 13th and 14th century records show various spellings: Stethyana, Stediana, Stedyan, Stediane, and Stidianus. The Rev. Sabine Baring-Gould's "Cornish Dedications" (1906) makes a connection with St Etaine of Tumna in Ireland, while Rev Michael Warner (Vicar of Stithians 1983-1993) suggests St Stephen. The saint's feast day is the Sunday nearest 10 July, and Stithians Show is held on the Monday following Feast Sunday.
There has been a church on the site since the 6th century, but the oldest part of the current church is 14th century; and the imposing tower was added in the 15th century. The former ecclesiastical parish of Carnmenellis is now merged with Stithians parish. The church has a large two manual pipe organ.
There are four Cornish crosses in the parish; they are in the vicarage garden, and at Repper's Mill and Trevalis. The cross at Repper's Mill has a crude crucifixus figure on the front and a Latin cross on the back. There are two crosses at Trevalis: both have a crude crucifixus figure on the front and a Latin cross on the back. One of the crosses formerly stood at Hendra Hill near the churchtown but was moved to Trevalis about 1860. Another cross stands in the grounds of Tretheague House.