The 23-year-old defender, who played the second half of Tuesday’s 3-0 win at Deal Town, has signed a one-year-deal.
Gallifuoco is no stranger to the National League after spending the 2016/2017 season with Torquay United.
He made thirty-five appearances for the Devon side in that time, including both games against Dover. He also scored 3 goals.
Born in Sydney, Gallifuoco joined the Gulls last year after a season with A-League side Melbourne Victory.
Gallifuoco first came to England to join Tottenham Hotspur when he was 18 in 2012 and he spent two years with them before leaving for Swansea City.
He spent a year in Wales before heading back home to play in the A-League.
Able to play in central defence, central midfield and at right-back, Gallifuoco has represented Australia at under-17, 20 and under-23 level.