The club announced on their official websiteon Wednesday that the Shrewsbury Town pair, both of whom have previously worked with Ipswich manager Paul Hurst, will join the club with immediate effect, with Nsiala set to wear the number 22 shirt while Nolan will be given the number 11 shirt.
Both Nolan and Nsiala came through the academy at Everton with each other before leaving Goodison Park in 2011 and 2012 respectively.
The two players both went their separate ways, with defender Nsiala even having a spell in Vietnam, before briefly reuniting once again on the books at Grimsby Town in 2016.
Nolan and Nsiala then found their ways to Shrewsbury Town in 2017, via spells at Chesterfield and Hartlepool respectively, where they went to to make a combined 134 appearances across all competitions - including in their play-off final defeat to Rotherham.
The two players will become Ipswich's fourth and fifth permanent signings of the summer, while a number of youngsters have also joined on loan, most notably Chelseateenager Trevoh Chalobah.