The House of Peers (貴族院 Kizokuin) was the upper house of the Imperial Diet under the Constitution of the Empire of Japan (in effect from 11 February 1889 to 3 May 1947). Ito Hirobumi and the other Meiji leaders deliberately modelled the chamber on the British House of Lords, as a counterweight to the popularly elected House of Representatives (Shūgiin).

In 1869, the leaders of new government had the Emperor Meiji issue an imperial ordinance that merged the daimyo and the kuge into a single aristocratic class, the kozoku. A second imperial ordinance in 1884, grouped the kazoku into five ranks equivalent to the European prince (or duke), marquis, count, viscount, and baron.

The House of Peers originally comprised:

  1. all imperial princes (shinnō) and lesser princes of the imperial blood (ō) over the age of twenty,
  2. all princes and marquis over the age of thirty,
  3. 150 elected representatives of the counts, viscounts, and barons,
  4. 150 additional members nominated by the Emperor, in consultation with the Privy Council, and
  5. 66 elected representatives of the 6,000 highest taxpayers.

During the first session of the Imperial Diet (1889-890), there were 145 hereditary members and 106 imperial appointees and high taxpayers, for a total of 251 members. With the creation of new peers and the addition of seats for representatives of the Imperial Academy (Gakushuin), the membership grew to 403 by 1925. The House of Peers elected its own president and vice president. Like the House of Representatives, the House of Peers had limited powers. The Constitution of Japan, in effect from 3 May 1947, replaced the unelected House of Peers with an elected House of Councillors.