The 20-year-old left-back played 11 league games and four cup ties for the Reds as his first season in professional football ended in them returning to the Championship after relegation a year earlier.
Williams told the Chronicle: “I was at the club when they were relegated and it was really hard for everyone but to come back within one season shows the class we have. “It’s been unbelievable and it is hard to put into words how good it’s been.”
Daniel Stendel gave Williams his league debut in the 4-0 win at Peterborough United in October. He said: “I have been surprised by how much gametime I have had this season. When the gaffer came in at the start of the season, he brought a style of play that suited me. It was a proud moment to make my debut and with the way the game happened in a top-of-the-table clash, it went in my favour. I was buzzing and from that moment on I just thought ‘I need to kick on now’ and that’s exactly what I did.”
Williams is now looking forward to the Championship and visiting both his hometown club Preston North End and Blackburn Rovers, where he came through the academy before moving to Barnsley.
Williams said: “Coming through at Blackburn it would be great to go back there and hopefully get three points. The season is done and we’ve celebrated so I will be working hard in the off-season to come back strong in the Championship. That’s what the fans will be expecting from all of us.”
Williams’ breakthrough season has earned him his first senior call-up to the Wales squad. He is currently training under Ryan Giggs and alongside Real Madrid star Gareth Bale as well as his fellow Barnsley promotion heroes Kieffer Moore and Adam Davies. They are due to play two away matches in the European Championship qualifiers over the next week. Williams, who has represented Wales at youth level, made the cut for the final squad after initially being named in the training camp squad. He wrote on Twitter: “An honour to have been called up again for the upcoming games.”