(Peter) Rigby Wason (1797 – 24 July 1875)^[1] was a Scottish barrister and farmer,^[2] and a Whig politician. He was Member of Parliament (MP) for Ipswich in Suffolk from 1831 until his defeat at the 1835 general election. However, the election was declared void on petition,^[3] and he was returned to the House of Commons at the resulting by-election, holding the seat until he was defeated again at the 1837 general election.^[3]

He regained the seat at the 1841 general election, but that election was overturned on petition and he did not stand again.^[3]

Wason married Euphemia McTier.^[2] Their children included Cathcart Wason (1848–1921), a New Zealand settler and MP who returned to Scotland and became MP for Orkney and Shetland, and Eugene Wason (1846–1927), a lawyer and Liberal MP.^[2] Peter Cathcart Wason was Eugene's grandchild.^[4]