St Davids 9 is an incomplete cross-carved stone with inscriptions. It is located in St Davids Cathedral (NPRN 306), behind the high alter in the Chapel of the Holy Trinity, where it is built into the front of the alter adjacent to St Davids 7 (NPRN 423496). It was first noted during restoration of the cathedral before 1925.

The stone is of Caerbwdy Sandstone and may have had a rounded top. Dimensions are given as 59.5cm height x 25.5cm width. Only face A is visible, and the upper right side and part of the top and left side are missing. The upper half contains an outline equal-arm ring-and-circle cross, carved in low, flat relief. The ring links the end s of the cross-arms, and around it is a narrow outer ring. The ross is decorated with finely-incised interlace, with a circle of ring-knots in its centre. Around the outer edge of the four quadrants (within the ring) is a lightly incised roman-letter inscription. It has been translated as `Matthew, Mark, Luke, John?. Below the cross are a number of finely incised arcs and circles, some of which overlap.

Sources include:
Edwards, N. 2007, Corpus of Early Medieval Inscribed Stones and Stone Sculpture in Wales

N Vousden, 26 October 2018