Town have also extended loan deals and been boosted by the return of some of their youngsters from loan spells. See who arrived and returned this January in our gallery.
Harvey Saunders is Town's only permanent signing of the window thus far.
He joined from Darlington for an undisclosed fee but went straight back to the National League North club on-loan until the end of the term.
Centre-half Harry Souttar joined on-loan until the end of the season from Championship Club Stoke City
Lewie Coyle extended his loan spell from Leeds United until the end of the term. The right-back was initially signed until January but will remain at Highbury until the summer.
James Husband extended his loan spell from Norwich City until the end of the term. The left-back was initially signed until January but will remain at Highbury until the summer.
Ashley Nadesan returned from his nine-goal loan spell at Carlisle and has gone straight into Joey Barton's first team.
Sowerby spent the first half of the season on-loan at Carlisle United but has just returned to Fleetwood.
The 23-year-old is now in contention to feature in Town's clash with Charlton at Highbury on Saturday.
Fleetwood Town made a third signing on transfer deadline day but the club are yet to reveal the identity of the mystery man.