Relegation-threatened Livorno have sacked Domenico Di Carlo after just 88 days in charge and re-appointed Davide Nicola.
Virgil van Dijk claims he knows nothing of interest from English clubs and is keen to prove himself in the Champions League with Celtic.
The defender becomes Mick McCarthy's first signing of the January transfer window and will remain at Portman Road until January 29.
Kisnorbo has been given clearance by his parent club to feature in Town's FA Cup third-round tie at Aston Villa on Saturday.
The 31-year-old Australian moved to Britain when he joined Hearts in 2003 but switched south of the border to join Leicester two years later.
After four years with the Foxes he linked up with Leeds, where he has made a total of 58 appearances although only one of those has come this season, a Capital One Cup outing in August.