On 4th January 2008, Norwich City signed 18 year old Chelsea left-back Ryan Bertrand on loan until the end of the 2007/8 season

Bertrand, a Chelsea trainee, had made appearances in Chelsea Reserves and had one England U19 cap at the time. He had spent three spells on loan - two with Bournemouth in 2006/7 and the first half of the 2007/8 season with League One side Oldham Athletic, where he made 22 appearances.

Glenn Roeder is quoted on the Canaries' official site as saying: "We have been following Ryan at Oldham and we've been very impressed. We believe he can step up to the Championship and help us to pick up as many points as we can."

“He comes to me highly recommended,” said Roeder. “As always I make sure I do my homework. I asked a lot of people, including, although he might not have seen a lot of Ryan around the place, Joe Cole, who I am very close to at Chelsea. He said, 'Glenn everything I have seen or heard has been very positive that Ryan's got a big future in the game', and he did extremely well at Oldham. Mark Crossley, his goalkeeper at Oldham who Lee Clark is very close to, we quizzed him about Ryan and everything was good. Robert Fleck, who scouts for the club now, watched him at Southend and said he was probably the outstanding player on the pitch, and ready to step up to Championship level. Frank Arnesen (Chelsea sporting director) told me there were at least three other Championship clubs that wanted to take Ryan, but Frank was particularly keen because of the experience that Jimmy (Smith) had here to point Ryan in our direction. It is good news for the club that young players want to come and further their careers at Norwich City.”

Bertrand provides instant competition for Mo Camara, who was brought in in November to cover for long-term injury absentee Adam Drury.

Ryan Bertrand added: "I'm really looking forward to playing for such a big club as Norwich City. I knew Norwich had been looking at me over the last month or so and once I heard they wanted me having only come back from my loan at Oldham yesterday, then I was straight up here. It's brilliant to get a chance to play here and I see it as the next stage of my career."

Ryan made his full City debut in the 3-1 away win at Barnsley on 12th January 2008. He finished the season with 20 appearances and a regular spot in the first team.

A variety of papers reported on 29th June 2006 that Bertrand was a target for Premiership new boys Hull City. Instead, Bertrand was loaned again to Norwich on 4th July 2008, initially until January but Glenn Roeder stated: “There is a possibility, after speaking to [Chelsea sporting director] Frank Arnesen, that he will be able to stay the whole year.”

Ryan made 40 appearances for City during 2008/9 but missed the final day of the season clash at Charlton where a 4-2 defeat saw Norwich relegated

In July 2009, Ryan was loaned out again, this time joining Reading who are managed by former Chelsea youth and reserve team coach Brendan Rodgers. He made 51 appearances for Reading

On 5th August 2010, Ryan was loaned for six months to Notts Forest, becoming their first signing of the summer.

In mid December 2010, it was reported that Forest were keen to make Bertrand’s loan permanent. 'There are two options, one is to extend and one is to buy him and I've made my recommendation,' said Forest boss Billy Davies. 'We'll wait and see what happens - we're looking at all options. It's in the hands of other people. In any great side you build from the back and that is very important. We'll see what develops. We'll keep asking the questions.' Bertrand retured to Chelsea when his loan expired on 3rd January 2011 - he had made 19 appearances for Forest.

In June 2011, Ryan was linked by The Mirror with a loan move to Swansea for the 2011/12 season, He made his breakthrough into the Chelsea first team at the end of the 2010/11 season

Bertrand made his European debut for Chelsea in the Champions League Final against Bayern Munich on 19th May 2012, playing in the starting XI and putting in a good performance although substituted late in the game. Chelsea won the final on penalties after extra time.

On 2nd July 2012, Ryan was named in Team GB's football squad for the 2012 London Olympics. He played in four games during the 2012 Games. On 15th August 2012, he made his debut for the England senior team in a friendly against Italy, ending in a 2–1 win. In his second international appearance, Bertrand came on after 73 mins against Ukraine and crossed the ball that led to the penalty that Frank Lampard converted.

He was called up in October for the World Cup qualifying games against San Marino and Poland but was sent home by the England medical squad suffering from a virus. Riled by suggestions his withdrawal from the England squad was due to a "sore throat", he posted on Twitter that his illness was more serious than had been suggested, adding: "Do you think a 'sore throat' could stop me being a part of a match for my club or country? #yourfuckingnuts this is what every boy dreams of." The message was subsequently deleted, an apology issued and his account appears to have been closed. The outburst came three days after the FA spoke with England's players at St George's Park about a new code of conduct. Yet, while the timing was unfortunate, there is sympathy within the England set-up for Bertrand's sense of frustration and the player will not be punished for his remark. "It's another reminder of how careful players have to be but his sentiments were laudable," said the England manager, Roy Hodgson. "They showed how much he wants to play for England and he was a bit irritated that someone suggested he doesn't play when he gets a sore throat. His choice of words was wrong. But I'm pleased he has apologised for it. It reminds us how unbelievably careful players of his profile have to be.

In July 2013, he was linked with a switch to Liverpool but opted to stay at Stamford Bridge and fight to succeed Ashley Cole as Chelsea's first choice left back.

After making just three appearances for Chelsea in the 2013/14 season under new manager Jose Mourinho, Bertrand was allowed to join Paul Lambert's Aston Villa on 17th January 2014 on loan until the end of the 2013/14 season. He made his debut the following day in the 2-2 draw at Liverpool as did fellow loan signing Grant Holt.. In total Bertrand made 16 appearances for Villa.

On 17th May 2014 a number of newspapers linked Bertrand with a £7million switch to Liverpool.

On 30th July 2014, Bertrand joined Southampton on a season long loan from Chelsea. According to the Press Association, there is an option for Southampton to make the deal permanent for up to £10m. His arrival was seen by Saints fan as evidence of a lack of ambition, replacing the promising England international Luke Shaw with a journeyman player on his ninth loan spell from Chelsea. However Bertrand flourished at St Mary's in 2014/15 and by the end of January 2015 had played 26 games, scoring twice as Southampton challenge for a Champions League place. Southampton signed him for £10million on 2nd February 2015, making him the fourth most expensive British transfer of the Winter 2015 transfer window.

Bertrand was recalled to the England sqaud for the 31st March 2015 friendly against Italy. He remained in the squad and was selected in the final 23 man squad for the European Championship in France in the summer of 2016. he played in their third group game, a draw against Slovakia on 20th June 2016.

On 4th May 2017, the Daily Mirror reported that Liverpool and Chelsea were both planning to sign Bertrand in the summer, with the full-back ready to leave Southampton. On June 5th 2017, it was reported that Man City would sign Bertrand after missing out on Monaco's Benjamin Mendy whom the French side wanted £40million for.

On 12th May 2021 Bertrand reported that he would be leaving Southampton at the end of the 2020/21 season. He had made 240 appearances, scoring eight goals. Bertrand said: "It has been a difficult decision but the time has come for me to seek a new challenge." It has been speculated that he would be joining Arsenal. Sky Sports thenclaimed on 2nd July 2021 that Bertrand has agreed a two-year deal with Leicester City after leaving Southampton when his contract expired. The move to Leicester was confirmed on 17th July 2021 with Bertrand signing a two year contract. Bertrand said: “I’m really happy to be here; joining Leicester really complemented my inner ambitions and what I still want to achieve in my career. Leicester have built something amazing over the years, especially since Brendan Rodgers has come in. It’s fantastic to be a part of this fantastic club and I’m going to give my all to try and do the fans proud.”

He was released by Leicester on 5th June 2023 alongside Youri Tielemans and Caglar Soyuncu, Daniel Amartey, Nampalys Mendy, Ayoze Perez and Tete.

In August 2023 he was linked with signing for Manchester United who were experiencing an injury crisis at left-back with Luke Shaw injured.

On 18th June 2024 Bertrand announced his retirement