Gweirca ferch Owain (possibly Gwerica) was a medieval Welsh noblewoman, granddaughter of Madog ap Gruffydd Maelor and daughter of Owain ap Gruffydd ap Madog.
Gweirca died in 1290 and is buried at Valle Crucis Abbey, near Llangollen, which was founded by her grandfather.
However, the following details can be identified: "an inscription, placed within a border, surrounding a narrow band of decoration.
The lower part of the panel has interlacing stems.
"[1][page needed] The inscription in Latin reads: Translated as: Peter Lord states that Gweirca's grave slab is "the earliest-dated Welsh memorial of any kind".