Christos Tzolis became the second Greek international to join Norwich when he followed Dimitris Giannoulis to Norwich from PAOK. After weeks of speculation and haggling, Tzolis signed for Norwich on a five year deal on 12th August 2021 for an undisclosed fee reported to be £10.8million. Tzolis said: “I would like to thank everyone for the very good welcome. I’m very happy to be a part of this team and I hope to see the fans as fast as possible. I spoke with the coach (Daniel Farke) and he told me the plan and what he will do with me in the team. It’s a very good project for me to sign here. From the first moment, I was really excited to come here. I said to my agent to sign as fast as possible here. It’s a very good step for me. "

After sitting on the bench for the Canaries' Premier League clashes with Liverpool and Manchester City, the Greek wonderkid winger/attacker made his Norwich debut starting in the 6-0 defeat of Bournemouth in the League Cup on 24th August 2021 and scoring twice.

He began his career with his village team Doxa Pentalofos. playing for them from 2006 until 2010, before joining PAOK. In 2015, the then 13-year-old impressed at the Lennart-Johansson-Cup, a tournament for 13 to 14-year-olds. The right-footed winger scored 11 goals in five games and guided his team to the final. Despite losing the final he won the golden boot and was voted the best player of the tournament.  According to his wikipedia article, he spent 2016/17 and 2017/18 with German sides SG Rosenhöhe Offenbach and SV Alemannia Königstädten respectively before rejoining PAOK in 2018, becoming a prolific scorer for their Under-17 side.

He broke into the PAOK senior team in 2020, Tzolis has gone on to make a total of 57 appearances in all competitions, scoring 17 goals. In 2020/21 he scored 16 goals and registered 10 assists in 46 appearances as PAOK finished second in the league and won the Greek Cup and featured in both Champions League and Europa League competitions. He was named the club's most valuable player.

After playing for Greece at Under-17 and Under-19 level, he made his full international debut on 7th October 2020 as a late substitute in a defeat to Austria. He was the seventh youngest player to represent Greece. His first international goal came the following month against Cyprus. At the time of his transfer to Norwich, he had played seven times for Greece scoring once.

Tzolis made just 17 appearances in his debut season with Norwich, 11 of those coming from the bench and failed to add to his two goals scored against Bournemouth in the League Cup. City were relegated.

In June 2022 he was linked with moves to Club Brugge and Feyenoord. Borussia Monchengladbach, who recently appointed former Norwich boss Daniel Farke as their new manager, are also said to be keen on the 20-year-old. He finally joined Dutch side FC Twente on loan on 22nd July 2022.

"It's important he gets plenty of game time, at a high level, over the course of this season," said assistant sporting director Neil Adams."We'll of course keep a very close eye on his development and progress, with the ultimate aim of him returning and contributing to what we're building here at Norwich City."

Tzolis' loan in Holland was ended early in January 2023 and he returned to Carrow Road with the expectation he would be part of David Wagner's first team squad. He made his second debut for City on 4th February 2023 in the 3-0 home defeat to Burnley. He made a further 12 appearances, scoring once.

On 6th August 2023 he joined German side Fortuna Dusseldorf on a season long loan. The German club have inserted a permanent option, which would see City recoup a major chunk of what they spent on the Greek international, into the deal. Tzolis will be competing in the second tier of German football with Dusselforf recording a fourth-placed finish in the 2022/23 season. Norwich boss David Wagner said "He needs now a move, or a team where he can start 30 games, and I can't see this happening here, I had very clear and honest conversations with Christos, and he didn't play a lot in the last two seasons. But he's a talent and this is why, for his career, it's so important that he finds a club where he maybe can start games."

On 22nd February 2024 it was reported that his 11 goals in 19 appearances had attracted the attention of Bundesliga sides. There were reports of a plan by Dusseldorf to activate the clause in the loan agreement to by Tzolis and then sell him on to a bigger club. Wolfsburg and Borussia Monchengladbach have been credited with an interest.