Right-back Peltier made three appearances for Liverpool in the League Cup and featured in an irrelevant Champions League game in Istanbul during the 2006/07 season. This turned out to be the only games he ever played for the club. Peltier was loaned out to Yeovil Town in League One in 2007/08 during which he was put under the spotlight in a couple of games by former player, Steve Claridge for the Guardian. "He was quick to close down opponents all over the pitch but he maintained that nice balance between stopping his winger and being in touch with his centre-half to utilise the pace he has on the cover," Claridge said, who was not impressed by him in the first game he saw when Peltier was a midfielder. "To reinforce the fact that right-back is his best position, he seemed to see a pass quicker, release himself from deep at the right times and be positive every time he looked forward." Claridge concluded that Peltier could thrive among better players and have a bright future in the game. Following his successful loan spell at Yeovil he was sold to the West Country club in January 2008.
At the end of June 2009 Huddersfield Town signed Peltier on a three-year contract. Manager Lee Clark had been impressed by Peltier when he had a trial spell at Norwich where he was assistant manager. Clark was excited by his new signing: "He is a fantastic athlete and is very accomplished on the ball, as you would expect given he was schooled at Liverpool. He will be a tremendous asset. He can also play as a holding midfield player or at centre-back." Peltier was voted his teammates' player of the year at the end of his first season in Yorkshire and was a regular as well in his second year when Huddersfield reached the play-off final, where they lost to Peterborough United. Peltier was signed by Sven-Göran Eriksson at big-spenders Leicester City before the 2011/12 season, moving up a level to the Championship. Eriksson was soon dismissed but Peltier enjoyed a good season, appearing in 40 League matches, adding to his ever-growing reputation. Twenty-five-year-old Peltier joined Neil Warnock's Leeds United in the Championship in August 2012. Although Warnock left towards the end of the 2012/13 season, Peltier appeared in forty-one of Leeds United's forty-six matches in The Championship. The Yorkshire club finished in thirteenth position, as far away from the play-offs as they were from the relegation places.
Peltier made 22 league appearances for Leeds in the 2013/14 season before moving on loan to Nottingham Forest towards the end of March 2014. He played seven times for Forest before the end of the season. Leeds then terminated his contract a year early, allowing him to rejoin Huddersfield, but the following January he was on the move again, penning a three year deal with Cardiff City where he played 41 league games in 2015-16. In 2017-18 Peltier won promotion with Cardiff, but then suffered a blow early in the Premier League campaign when he dislocated his shoulder. Although he was able to force his way back into the side for the second half of the season, he couldn't help prevent relegation back to the Championship. He was a regular at right back for the first half of 2019-20 but then joined West Bromwich Albion in the January transfer window amidst rumours of a fallout with the manager and contractual dispute. Despite not featuring at all for the remainder of the season, he remained at The Hawthorns for 2020/21 and played in the first two rounds of the League Cup. He made three Premier League starts as the Baggies were relegated and in July 2021 agreed a one year deal with Middlesbrough. Peltier was an able deputy at the Riverside, filling in across the back four and in midfield but he was released at the end of the season as manager Chris Wilder sought to rebuild the squad.