Midfielder Foxley joins from fellow National League South side Hungerford Town.
He was instrumental as the Crusaders evaded the threat of relegation which included a 5-0 thumping of his new team.
Needless to say, the Saints' boss is happy to see him sign on the dotted line.
“He absolutely tormented us when we played Hungerford last season and remember both Glen (Alzapiedi) and myself singled him out as an outstanding player," Allinson told the club's website.
"He likes to take on defenders and with the pace he has, I’ve no doubt he’ll prove to be a massive asset.”
Former Northampton striker Iaciofano was on trial Clarence Park and has clearly done enough to impress his new boss.
“We needed to bolster the attacking options and Joe will offer something different for us going into the new season," Allinson said.
"He’s young but he brings a level of physicality that I feel we were missing towards the end of last season."
St Albans City get their 2019/20 National League South season underway against Chippenham Town on August 3.