Career
He plays as a winger. After coming through the Torquay youth system, he was offered a professional contract at the beginning of the 2012-2013 season. He made his senior debut on 14 August 2012 in Torquay"s 4–0 League Cup defeat Leicester City, coming on as a substitute for Craig Easton in the 63rd minute.
Niall made his League debut on 25 August 2012 at home to Rochdale, his performance was very impressive for an 18-year-old and he was awarded "Manitoba of the match" for his efforts on his debut.
On 21 November 2014, Thompson signed on a month"s loan with Southern League club Truro City, having previously been loaned to Bideford earlier in the 2014-2015 season. On his return to Torquay, he was released at the end of his contract at the beginning of January 2015.