holier-than-thou

[hoh-lee-er-th uh n-th ou]

obnoxiously pious; sanctimonious; self-righteous.

a person who is obnoxiously pious or self-righteous.

Origin of holier-than-thou

First recorded in 1910–15

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Herman likes to give the appearance of living this holier-than-thou life.
Herman Cain's Marriage Shaken by Infidelity Charges
Allison Samuels
December 2, 2011
Unfortunately for Edwards, the holier-than-thou approach won her few fans.
The Year in Talk: 2009's 19 Most Pivotal Moments
The Daily Beast Video
December 24, 2009

I've watched the lot of you Cavendishes, with yer stuck-up 'holier-than-thou' ways.
The Lone Ranger Rides
Fran Striker
But I don't want you to think you can get away with any holier-than-thou stuff.
Babbitt
Sinclair Lewis
There's going to be one house in this scandal-mongering town to-night that isn't going to spring the holier-than-thou.
Babbitt
Sinclair Lewis
To one who goes to Spain in the holier-than-thou attitude, she is dumb and repellent,—she who can be so eloquent!
Heroic Spain
Elizabeth Boyle O'Reilly
Happily the generations of cant and holier-than-thou are passing, and we are looking history more honestly in the face.
Heroic Spain
Elizabeth Boyle O'Reilly

Word Origin and History for holier-than-thou

as an adjectival phrase in reference to supercilious sanctimony attested by 1888, American English. The text is in Isaiah lxv:5.