Career
He made 40 appearances in the Football League for Wrexham in the 2005-2006 to 2007-2008 seasons. In the following month, he made his debut for the Wales Under-21 side against Northern Ireland Under-21. He scored two goals in his next game for the Welsh Under-21 side against Israel Under-21 in August 2006.
Williams signed a new contract with Wrexham in summer of 2006 and made 17 league and cup appearances for Wrexham in the 2006-2007 season.
He made a further 23 league and cup appearances in the 2007-2008 season as Wrexham were relegated from the Football League. Williams contributed to Wrexham"s bid to return to the Football League with 15 goals (13 league and 2 cup) including a hat trick against Eastbourne Borough on 20 December 2008.
However, on 28 February 2009, he suffered a broken foot in a match against Salisbury City, which ruled him out for the remainder of the season. After injury disrupted the majority of Williams" 2009-2010 season, he was handed a six-month deal to prove his fitness.
However, with the arrival of Andy Morrell, he found himself out of favour at the club and instead joined Kidderminster Harriers on loan in August 2010, scoring on his debut in a 4–3 defeat to Southport.
He signed for Chester on 20 February 2012 on a deal which takes him to the end of the season. Marc scored his first 2 goal"s for Chester in the 3–2 victory over Bradford Park Avenue both before half time. He added his 3rd Chester goal in the 2–0 victory at Chorley.
At the end of the 2012 season, Marc signed a 1-year professional contract with Chester.
He was released by the club on 22 May 2013 after he wasn"t offered a new contract. Marc said he was "shocked and massively disappointed" after not being offered new terms.
He left Chester with 14 goals and 60 appearances in all competitions within one and half season. He spent a short spell with Northwich Victoria F.C. before joining Colwyn Bay in October 2013.