Welsh republicanism (Welsh: Gweriniaetholdeb Gymreig) or republicanism in Wales (Welsh: Gweriniaetholdeb yng Nghymru) is the political ideology that advocates for Wales to be governed by a republican system, as opposed to the monarchy of the United Kingdom.
Typically, this ideology is suggested as an element of forming an independent Wales, but can also be considered as part of reforming the political system of the United Kingdom, which could include introducing an elected official as head of state. It is not synonymous with Welsh independence, but one possible form of government, as Wales before English rule had native monarchies, and most of the prominent independence organisations do not explicitly support republicanism. While the Wales Green Party supports a republic and would support independence in a referendum.