18-year-old Leak, who turned professional alongside Luke Little in the summer, will be available for selection this weekend as Steve Claridge's Salisbury take on Hendon.
Tom, a former captain of the club's under-18s side, is yet to make a first-team appearance for the Saddlers and is looking forward to his first loan spell away from the Banks's.
Speaking ahead of the move he said; "I’m buzzing. It’s a good level for me to go and perform so I’m hoping to gain valuable experience in terms of men’s football and being in a first team environment.
"The intensity of training with the first team here keeps me at a good fitness level so I’m ready to go and play games and I’m really excited."