The 29-year-old forward has joined the Sky Blues ahead of Friday's opening Premier League clash against defending champions Arsenal, with Frank Lampard's side returning to England's top-flight for the first time in 25 years.
Awoniyi has spent the last four seasons with Forest, scoring 23 goals in 103 games, and was given a guard of honour by the squad and staff before the second half of their final pre-season friendly against Brest on Sunday to allow him to say goodbye at the City Ground.
Forest head coach Oliver Glasner said: "Everybody in the club likes him and I could see everybody in the stand likes him because this is what everybody appreciates.
"He always gives 100% for the team, he always gives 100% for the bench, and that's why he deserves such a farewell, such a guard of honour.
"That's why we decided we would give it to him and I wish him all the best at his next club, just not when they play us."
Awoniyi's signing continues a succession of incomings for Coventry ahead of the new season, having already re-signed midfielder Gus Hamer from Sheffield United and goalkeeper Carl Rushworth, following his successful loan from Brighton.
Winger Loum Tchaouna has joined from Burnley, defender Aurele Amenda arrived from Eintracht Frankfurt and Ghana international Caleb Yirenkyi signed from Nordsjaelland.
Liverpool coach Andoni Iraola was satisfied that his team kept a clean sheet but admits they need more work after wrapping their pre-season friendlies with a 2-0 victory against Italian side Como.
Mikel Arteta has moved to reassure Arsenal fans over his future at the club, insisting there is no reason for concern despite having only 12 months remaining on his contract.
Barcelona remain in discussions with Manchester City over a potential deal for Rodri, with the Spanish midfielder already having agreed personal terms with the Catalan club.
Jeremy Doku has expressed his delight after signing a new five-year contract extension with Manchester City.
