The Shadow Cabinet (also called the Opposition Front Bench) is a senior group of opposition spokespeople in the Westminster System of government who together under the leadership of the Leader of the Opposition (or the leader of other smaller opposition parties) form an alternative cabinet to the government's, whose members shadow or mark each individual member of the government. Members of a shadow cabinet are often but not always appointed to a Cabinet post if and when their party gets into government. It is the Shadow Cabinet's responsibility to pass criticism on the current government and its respective legislation, as well as deciding where amendments to the legislation are necessary.

In the United Kingdom and Canada the major opposition party and specifically its shadow cabinet is often called Her Majesty's Loyal Opposition. The adjective "loyal" is used because while there are policy differences, everyone acknowledges the role of the opposition in the system. However in other countries that use the Westminster system (eg. Australia and New Zealand), the opposition is known simply as The Parliamentary Opposition.

Some parliamentary parties, notably the British Labour Party and the Australian Labor Party, elect all the members of their shadow cabinets in a partyroom ballot, with the Leader of the Opposition then allocating portfolios to the Shadow Ministers. In other parliamentary parties, the membership and composition of the Shadow Cabinet is generally determined solely by the Leader of the Opposition.

List of Shadow Cabinets

• Australia
  • Official Opposition Shadow Cabinet (Australia) (Labor)

• Canada
  • Official Opposition Shadow Cabinet (Canada) (Conservative)
  • Bloc Québécois Shadow Cabinet
  • New Democratic Party Shadow Cabinet

• Ireland
  • Irish Opposition Front Bench (Fine Gael)

• UK
  • Official Opposition Shadow Cabinet (UK) (Conservative)
  • Liberal Democrat Shadow Cabinet