The 2017–18 Welsh League Cup (known for sponsorship purposes as The Nathaniel MG Cup) was the 26th season of the Welsh Premier League's cup competition, which was established in 1992. Played under a regionalised, knock-out format, the 2017-18 competition was the fourth to be held since the tournament was expanded to include clubs from outside the Welsh Premier League. As well as the 12 Welsh Premier League clubs from the previous season, the top five qualifying clubs from the northern and southern feeder leagues would enter the tournament, along with a number of wildcard entrants.