Born at Nant-y-glo, near Ebbw Vale in Monmouthshire, Evans was educated at the Beaufort British School and became a teacher at Gwynfe and Llangadog, Carmarthenshire. However, his ambition was to become a journalist.
As a playwright, Evans introduced a sceptical Nonconformity to drama with his nationalist play Owain Glyndŵr, performed at the Llanberis Eisteddfod of 1879. A member of the Gorsedd, he was heavily involved in Welsh language literature and publishing.
In 1880, Evans established the monthly magazine 'Cyfail yr Aelwyd,' and in 1887, he gave up teaching altogether for a career in journalism, joining the staff of the 'South Wales Daily News', Cardiff. At the same time, he edited the Welsh section of the 'Cardiff Times and South Wales Weekly News.' In 1892, he moved to Caernarfon to take up the post of managing editor of the Welsh National Press Co., publishers of 'Y Genedl Gymreig,' 'The North Wales Observer' and other papers. In 1917 he became editor of the Congregationalist weekly 'Y Tyst'.
Beriah Evans was an ally of David Lloyd George and the other North Walian present at the Newport meeting of 16th January 1896. As secretary of Cymru Fydd from 1895, Evans was in the vanguard of Cymru Fydd’s offensive across Wales. Lloyd George spoke against a motion to make Evans’ post merely an unpaid, honorary post at Newport “…and curiously enough we carried that.” Once Lloyd George had swung the meeting against this resolution, the decision was made to exclude him from any discussion on the second motion, that of the four sub-federations. The Cardiff Cymru Fydd society was known as ‘Beriah’s baumkin’. Beriah Evans would turn his hand to writing novels, and also produced a fine biography of Lloyd George. In his final years, Evans would join the infant Plaid Cymru. Evans broke with Lloyd George on the subject of the Boer War, being a Liberal Imperialist in his sympathies.