[6] The season began on 11 August 2017[7] and concluded in April 2018; the Europa League play-offs followed afterwards.
Teams played each other twice on a home and away basis, before the league split into two groups at the end of January 2018 – the top six and the bottom six.
On 26 April 2018 the FAW Club Licensing Appeals Body decided to revoke Bangor City's Tier 1 and UEFA licence[8] meaning that they would automatically drop down to the second level of Welsh football the next season and would not be able to compete for a place in the following season's Europa League.
Teams play each other twice on a home and away basis, before the league split into two groups – the top six and the bottom six.
Teams that finish in positions third to seventh at the end of the regular season will participate in play-offs to determine the third participant for the 2018–19 UEFA Europa League, who will qualify for the preliminary round.