The 26-year-old had one year left on his contract with Torino and was on the radar of Premier League’s Everton and Bournemouth this summer.
With Torino failing to hand him an extension, the former Hoffenheim midfielder decided to join the Blues who reportedly promised him regular game time.
"Empoli is pleased to announce that we have reached an agreement with Torino to sign Ghana international Afriyie Acquah until the end of the season," a club statement read.
"The player signed a contract until June 30, 2019 with a renewal option. He is also very experienced on international stage so we wish him the best of luck with us," the statement added.
Acquah scored six goals in 79 games with Torino across three seasons.
L'Empoli FC è lieta di annunciare di aver raggiunto l'accordo con il @TorinoFC_1906 per l´acquisto a titolo definitivo dei diritti alle prestazioni sportive di @AcquahAfriyie20. pic.twitter.com/NJiuaLGKhV— Empoli Fc Official (@EmpoliCalcio) 17 août 2018
He also boasts of 29 international appearances with Ghana after making his debut in 2012 against Chile in a friendly.