open letter

American  

noun

1. a letter, often of protest or criticism, addressed to a specific person, but intended to be brought to public attention.

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open letter British  

noun

1. a letter, esp one of protest, addressed to a person but also made public, as through the press

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Other Word Forms

• open-letter
  adjective

Etymology

Origin of open letter

First recorded in 1875–80

Example Sentences

See Examples For:

open letter

An Anthropic spokesman said people at all levels in the company are concerned about AI safety and that many employees had signed the pacing-the-frontier open letter in July.

From The Wall Street Journal ● Sep. 14, 2026

In an open letter last spring, faculty from the Gould School of Law said they were “unanimously opposed” to being included in it.

From Los Angeles Times ● Sep. 3, 2026

OpenAI, Anthropic and more than 100 other organizations signed an open letter last week calling for a coordinated global response to AI-related cybersecurity risks, warning that the window to strengthen cyber defenses was limited.

From Barron's ● Sep. 3, 2026

It also featured an open letter from 53 prominent women — including tennis great Billie Jean King, singer Judy Collins and Steinem — who revealed that they had undergone abortions.

From Los Angeles Times ● Sep. 3, 2026

It should, by all rights, be called the Farewell Letter, for it was in form and tone an open letter to the American people, telling them they were now on their own.

From "Founding Brothers: The Revolutionary Generation" by Joseph J. Ellis