Ada, Countess of Holland ( – 1234/37) was a countess-regnant and the co-regnant with husband Louis II of Loon.
Ada of Holland may also refer to:
Ada of Holland, Margravine of Brandenburg ( – after 1205) Ada of Scotland, Countess of Ross, Countess-consort of Holland (died after 1206) Ada of Holland (abbess) (1208–1258), abbess of Rijnsburg Abbey from 1239