19 year old Swindon midfielder Louis Thompson.was signed by Norwich on Transfer Deadline Day (1st September 2014) from Swindon for an undisclosed fee, believed to be around £600,000 but which could rise to £1.3million. He was immediately loaned back to Swindon for the remainder of the 2014/15 season.

Thompson has made 44 appearances for Swindon, where he came through the academy system along with his brother, Nathan, who was captain at the County Ground. Thompson made his first team debut for Swindon on 28th January 2012 as an 81st minute substitute for fellow Town midfielder Simon Ferry during the 2–0 away loss to Leicester City in the FA Cup Fourth Round.

He has been capped by Wales at Under-19 level and made his Under-21 debut in September 2015 against Luxembourg.

He was loaned back to Swindon on 11th September 2015 until December. His loan was renewed on 1st February 2016 until the end of the 2015/16 season.

Thompson finally made his Norwich debut on 23rd August 2016 in the 6-1 win over Coventry at Carrow Road in the Football League Cup. His league debut for Norwich came as a late substitute in the 2-1 away win at Nottingham Forest on 17th September 2016. He made a total of 6 appearances for City in 2016/17 before injury curtailed his season. He made eight appearances in an injury plagued 2018/19 season in which Norwich won the Championship title.

On 16th August 2019, he joined Shrewsbury on loan until the end of the 2019/20 season. "We're a little bit short in midfield, so it's important to bring those players in," said Town boss Sam Ricketts. "Louie's a great young player. Great player, great pedigree and great person. He's really dynamic."

On 2nd January 2020 Norwich recalled Thompson from his loan due to concerns over the lack of playing time (he had played 14 games for Shrewsbury).

On 16th January 2020 he joined MK Dons on loan, managedby former Norwich teammate Russell Martin. Thompson said "The team are playing a great brand of football and I wanted to get down here and be a part of that. Hopefully I can take to it like a duck to water."

He returned to MK Dons on a season-long loan on 18th August 2020. He made 21 appearances for MK Dons.

On 24th July 2021 Louis departed Norwich by mutual consent. On 1st August it was reported that he was training with Portsmouth but will need to prove his physical robustness if he is to earn a contract. His brother Nathan is already at Fratton Park. Thompson featured for Pompey in their final pre-season fixture against Peterborough, coming off the bench during the 2-0 victory. He now looks set to feature for their youth side against Bournemouth U23s. Manager Danny Cowley said: ‘We are taking a look to see where he is physically before we make a judgement call on whether he is right for our squad. Thompson signed a one year contract with Portsmouth on 10th August 2021

He was released by Pompey on 12th May 2023. He had played 57 games for them.

On 20th June 2023, he signed for Stevenage who had signed Thompson's older brother Nathan earlier that month.