1773 in Wales
- 22 April - An earthquake occurs in the Caernarfon area, with an estimated strength of 3.7.
- 7 November - Richard Morris makes his will.
- 26 November - Walter Siddons marries Sarah Kemble.
- Dolauhirion Bridge is built on the Llandovery to Cilycwm road by William Edwards.
- David Williams resigns from the ministry and opens a school in Chelsea.
Arts and literature
- Evan Evans (Ieuan Fardd) - Rhybudd Cyfr-drist i'r Diofal a Difraw
- John Roberts (Siôn Robert Lewis) - Geirlyfr Ysgrythurol
- 21 February, Titus Lewis, preacher and writer (died 1811)
- 14 November - Stapleton Stapleton-Cotton, 1st Viscount Combermere, military leader (died 1865)
- date unknown - Joseph Harris (Gomer), writer (died 1825)