The 22-year-old has put pen to paper on a five-year contract at the Coventry Building Society Arena, becoming Frank Lampard's first fresh addition of the summer transfer window.
A single season in England was enough to convince Coventry to move for the winger, whose spell at Burnley yielded three goals from 32 outings as the club slipped straight back out of the Premier League.
"I'm so excited to start this new season in the Premier League, I'm feeling good and ready for the challenge," the former France youth international said. "I was at Burnley last season in the Premier League, which was incredible.
"I'm going to bring my energy, determination and leadership to the team. I've played in Ligue 1, Serie A and now I'm playing in the Premier League, the best league in the world, so I have a lot of experience for my young age. I can't wait for the new season."
A Rennes academy product, he had a formative loan at Dijon before his career took him to Italy, first at Salernitana and then, from 2024, at Lazio, where his form in the Europa League included a goal at Ajax.
His only season in the Premier League brought mixed reviews, with Tchaouna spending long spells out of Burnley's starting line-up before finding better form towards the end of the campaign. He now swaps places with Coventry, who go the other way into the top flight after winning the Championship title.
The Sky Blues face a daunting opening assignment away at champions Arsenal on 21 August as they prepare for life back in the Premier League. Lampard has been strengthening his squad throughout the summer, with Tchaouna's arrival following Frank Onyeka's permanent move from Brentford being confirmed last month.
Coventry are expected to remain active in the transfer market as they bid to establish themselves following promotion, with Tchaouna seen as a marquee addition given the scale of the fee involved.
The move represents a significant profit for Burnley, who paid Lazio in the region of £12m for Tchaouna's signature only twelve months ago, as the Clarets look to balance the books following relegation.
For Coventry, landing a player with Tchaouna's pedigree across three major European leagues underlines their ambition to compete rather than make up the numbers back in the top flight.