[3] Haverfordwest County were promoted to the Cymru Premier despite finishing second, after league winners Swansea University failed to achieve a Tier One license.
The inaugural season consisted of twelve teams from the now defunct Welsh Football League Division One, which are Afan Lido, Ammanford, Briton Ferry Llansawel, Cambrian & Clydach Vale B.G.C., Cwmamman United, Cwmbran Celtic, Goytre United, Haverfordwest County, Llantwit Major, Pontypridd Town, Taff's Well[4] and Undy Athletic.
Joining them were Llanelli Town who were relegated from Cymru Premier and Welsh Football League Division Two champions, STM Sports together with runners-up, Swansea University and Caerau (Ely).
On 19 May 2020, the league was cancelled due to the COVID-19 pandemic and an unweighted points per game method was applied to determine the final standings.
Swansea University were declared champions but they failed to secure a Tier One licence for the 2020–21 season after an unsuccessful appeal and not be eligible for promotion.