Attacking midfielder Todd Cantwell was part of Norwich's Under 13s squad in 2010/11. As part of Norwich's Under-16 squad, he, in February 2014, was placed on standby for an England Under-16 development tournament at St George's Park.

Todd signed on as an Academy Scholar with Norwich on 8th July 2014 and will be part of the Under-18s side in 2014/15.

Cantwell scored for England's Under-17s on 29th July 2014 against Finland.

After interest from Arsenal, he signed his first professional contract with Norwich on 5th April 2016, which will keep him at the club until 2019.

Cantwell was included on the bench for Norwich's 1-1 home draw with Hull on 14th October 2017. He made his first team debut as a 86th minute substitute for Grant Hanley in the FA Cup Third Round replay at Chelsea which City drew 1-1 but lost on penalties in extra-time. He was replaced by Marco Stiepermann on 120 minutes ahead of the penalty shoot out.

He was loaned to Dutch second tier side Fortuna Sittard on 28th January 2018 for the remainder of the season so to gain first team experience. Daniel Farke said “I brought him on the pitch in a difficult game at Chelsea, which shows I trust him. But we have four new attacking signings, so it has become more difficult for Todd to get minutes.Now, at his age, it’s important he gets playing lots of games in a senior league, as he needs to step up from playing for the Under-23s. We hope he can get many minutes because he plays an important role in my plans for the summer.” Todd scored twice in 10 appearances, interupted by injury, to secure Fortuna's return to the Dutch top flight after a 16 year absence.

Todd made 27 appearances in Norwich's Championship winning season of 2018/19, scoring once against Rotherham in December 2018.

Cantwell made an impressive start to his Premier League campaign assisting Teemu Pukki with goals against Newcastle and scoring against Chelsea. At the end of August 2019, he was called up by England's Under-21s for their clashes with Turkey and Kosovo in September 2019. He made his England Under-21 debut against Kosovo on 9th September 2019, as an 81st minute substitute for Morgan Gibbs-White.

Cantwell's form for struggling Norwich and six Premier League goals by January 1 2020 saw him linked with Liverpool, Manchester United and Tottenham. On 10th July 2020 the Daily Star reported that Sheffield United were preparing a £10m bid for Cantwell A few days later he was linked with Leicester and Newcastle.according to the Daily Mail and the Sun. Bayern Munich, Manchester United, and Manchester City have all registered interest in the player as well..The next club to be linked were Aston Villa on 13th Augist 2020 wityh Cantwell seen as a replacement for Jack Grealish if he signed for Manchester United as expected. Emi Buendia was also linked. Cantwell had made 40 appearances for Norwich during 2019/20 scoring seven goals.

On 27th September 2020 Football Insider reported that Leeds had made a £15million bid for Cantwell. This coincided with him being dropped for the Canaries' trip to Bournemouth that same day due to poor performance in training the previous week. Cantwell unfortunately was then the subject of unpleasant tweets from Norwich fans.

Cantwell made 34 appearances, scoring six goals in 2020/21 as Norwich won the Championship title.

On 1st August 2021 it was reported that Norwich had set Cantwell's transfer fee at £40million if Aston Villa make enquiries following Manchester City's interest in Villa's Jack grealish for a reported £100m.

Cantwell dominated transfer window discussions relating to Norwich at the beginning of January 2022. Out of favour with new manager Dean Smith who had been frustrated by Cantwell's performances, it was speculated that Cantwell would be allowed to leave Norwich for £15m in order to fund new incoming transfers. Newcastle, with their new owners, were linked with a swoop although Sky Sports are reporting that another unnamed Premier League club is also keen on Cantwell. Some speculation online suggests that would be Liverpool. In the end Cantwell was loaned to Bournemouth on 31st January 2022 until the end of the season with a view to a permanent deal in the summer.

Bournemouth were promoted to the Premier League on 3rd May 2022. He had made 12 appearances for Bournemouth.

On 16th June 2022 he was linked with a loan to Blackburn Rovers for the 2022/23 campaign according to The Sun. The Sun's transfer expert Alan Nixon has claimed that Rovers' new head coach Jon Dahl Tomasson has targeted the City number 14, but a more relevant factor may be that the Lancashire club's new director of football Gregg Broughton was a key part of the Canaries' academy as Cantwell was coming through the ranks.

After speculation throughout January that Cantwell was free to leave Norwich, he was linked with Rangers and Dutch side PSV. He finally signed for Rangers on 23rd January 2023 for an undisclosed fee reported to be £1.5million. He had six months remaining on his Norwich contract and Canaries head coach David Wagner confirmed prior to the trip to Preston North End that the 24-year-old was not a part of his plans, after the former English youth international and his agent had been told they were free to search for a new club. He had played 19 games for Norwich during 2022/23 but struggled for form, not scoring or registering an assist.

Speaking about his move to Scotland, Cantwell said: "I am delighted and I feel very proud. This is obviously a massive football club, and I'm delighted to get going and to get started. This is a massive club and there is a massive responsibility when you sign for Rangers to be the player that the fans want to see. They want to see a player that works hard, and a player that can win them games, which is very important, and that's something I'm hoping I can bring." He made his Rangers debut on 28th January 2023 in a 2-0 home win over St Johnstone.

Cantwell had 15 goal contributions in 44 appearances during his first full season at Rangers, and featured in the qualifying stages of the Champions League and later the Europa League. Despite winning the Scottish League Cup, they lost to Celtic in both the League title race and the Scottish Cup final. But the midfielder is reportedly down the pecking order under Gers’ boss Philippe Clement, who is looking to overhaul his squad in the transfer window to challenge Celtic’s dominance north of the border. On 4th July 2024 the Scottish Sun claimed the Dereham-bred playmaker is a target for ambitious Saudi Pro-League side, Al-Qadsiah, who recently signed former Real Madrid star Nacho. Former Rangers chief executive, James Bisgrove, was appointed as the Saudi’s new CEO last week, who are 'closely monitoring Cantwell's situation'.

At the end of July 2024 it was reported by Rangers boss Phillipe Clement that Cantwell had handed in a transfer request and was looking for a new adventure. He was quickly linked with Cardiff City with a sum of £6million mentioned. In the end he signed for Blackburn Rovers on 30th August 2024 on a three year deal for an undisclosed fee.