Kingsmark, also recorded under the Welsh forms Cynfarch, Cynmarch, and Kynemark, was a fifth-century monastic figure associated with the early Christian foundations of south Wales. By tradition he originated in Scotland, where he is described as a chieftain, but he is honored in Wales, where he settled and where his memory was preserved. He is commemorated on September 8 and is reckoned among the pre-schism Western saints venerated as Orthodox.
According to the tradition received in Wales, Kingsmark was a disciple of St. Dyfrig (Dubricius), one of the principal saints of south Wales, who is remembered as an abbot, bishop, and missionary and who trained large numbers of clergy at his monastic foundations. The Book of Llan Dav records Kingsmark among Dyfrig's disciples. His sources are thin, and much of what survives concerning him comes through later Welsh hagiographical and topographical record rather than a contemporary life.
Kingsmark's memory is preserved principally through the places that bear his name. The settlement of Llangynfarch near Chepstow took its name from him, and churches in Wales were dedicated in his honor, among them a church at Llanfair Dyffryn Clwyd that contained a stained-glass window depicting 'Sanctus Kynvarch.' The wider distribution of dedications to him across Wales and the West Country reflects a local cult that endured after his death, when the Welsh faithful came to regard him as a saint.