On 30 August 2013, Nir Bitton signed a four-year deal with Scottish Premiership club Celtic, for a fee of around £700,000 and a 20% sell-on clause for Israeli Premier League club FC Ashdod.
He made his debut for the club on 18 September, in a Champions League group stage match against AC Milan, coming in to the game as a late substitute at the 89th minute. Three weeks later he made another Champions League appearance for Celtic, coming as a 77th-minute substitute against Ajax on 22 October, but was sent off eleven minutes later for a late tackle on Thulani Serero. The resulting suspension and a few niggling injuries hindered Bitton’s efforts to establish himself in the team, but he still managed to make a total of 20 appearances for Celtic by the end of his first season there. Celtic won their third successive league title, and Bitton’s 15 league appearances saw him pick up his first major honour.
In the 2014-15 season, Bitton scored in Celtic’s first league match of the season from the penalty spot after a controversial red card for St Johnstone defender Dave Mackay. Celtic winger Derk Boerrigter was later given a 3-match ban for simulation. Later in the season, Bitton scored a stunning 30-yard goal against Dundee. in a 5–0 win. He scored another long distance strike on 12 August 2015, netting from 25 yards into the top corner in a 2–2 draw with Kilmarnock.
To begin the 2015–16 season, on 19 August 2015 Bitton scored against Swedish side Malmö FF in a 3–2 win at Celtic Park in the first leg of the Champions League playoffs.