Mynydd-bach, also spelled Mynydd-Bach, Mynydd Bach, Mynyddbach and Mynydd-bâch, a Welsh word meaning a 'little mountain', may refer to the following places in Wales:
Mynydd-Bach, Swansea, also spelled Mynydd-bach, Mynyddbach, Mynydd Bach, district of Swansea Mynyddbach Chapel, chapel in Swansea Mynydd-bach (electoral ward), formerly Mynyddbach, electoral ward in Swansea Mynydd Bach (hills), hills in Ceredigion Mynydd Bach, Ceredigion, hamlet in Ceredigion Mynydd-bach, Monmouthshire, also spelled Mynyddbach, Mynydd-bâch or Mynydd Bach, hamlet in Monmouthshire Mynydd Bach Trecastell, hill in Carmarthenshire and Powys