Mynydd Meio is a 322-metre-high hill in the county borough of Caerphilly in South Wales.

Parts of its western slopes fall within Rhondda Cynon Taf county borough.

The hill is crossed by the Senghenydd Dyke, an ancient earthwork considered to date from the 13th century and associated with nearby Caerphilly Castle.

[2][3] Much of the upper part of the hill is mapped as open access under the Countryside and Rights of Way Act 2000 and thereby generally available to walkers.

It is also crossed by the Rhymney Valley Ridgeway Walk, a recreational path which in the immediate vicinity runs north from the hamlet of Groes-wen over the hill towards Cefn Eglwysilan.