Thank you in Welsh
Diolch
In Welsh, the phrase to know first is "Diolch!" (Thanks!). The others are below, each with a note on when to use it.
Thank you in Welsh is Diolch. Below are the stronger forms, "thank you from the heart", and the reply. Each phrase comes with a short note on when to use it.
Greetings
Diolch!
Thanks!
The everyday word.
Diolch yn fawr!
Thank you very much!
Literally "thanks greatly".
Diolch yn fawr iawn!
Thank you very much indeed!
Iawn adds "very".
Diolch o galon!
Thank you from the heart!
For heartfelt thanks.
Replies
Croeso!
You're welcome!
The usual reply to thanks.
About the words
Diolch goes back to Middle Welsh diolwch, from di- and iolwch, "grateful praise". Geiriadur Prifysgol Cymru defines it as thanks, thanksgiving and gratitude. O galon means "from the heart, heartily", which gives diolch o galon. Croeso, welcome, is also the reply to thanks.
Common questions
How do you say thank you in Welsh?
Diolch, or Diolch yn fawr, "thank you very much".
How do you reply to diolch?
Croeso, "you're welcome".
Thank you in the other Celtic languages
Further reading
Go beyond the phrases
blas. teaches Welsh with spaced repetition — vocabulary, mutations, grammar, reading, and conversation. Not just for Thank you, but for life. Free to start.
Start learning WelshWelsh phrases for the year ahead
Welsh phrases for everyday occasions
Sources
Every phrase and fact on this page was checked against the sources below. Last checked 2026-10-20.
- Wiktionary, via Kaikki.org
- Geiriadur Prifysgol Cymru: diolch
- Geiriadur Prifysgol Cymru: calon
- Wiktionary, via Kaikki.org
- Wiktionary, via Kaikki.org
- blas. course data
- Wiktionary, via Kaikki.org
- Tatoeba: Tatoeba #6443807 by Ricardo14, CC BY 2.0 FR
Credit: Wiktionary contributors, CC BY-SA 4.0.