Ford filed his nomination papers on Thursday, ensuring he was first in line at city hall to sign up for the Oct. 27 mayoral election on the day registration opened.
Ford has said he intends to win another term leading Canada's most populous city, despite a rough year that saw him admit to using crack cocaine in a "drunken stupor," among other incidents.
Soknacki, a former budget chief during his time on council, says he wants to see higher standards in the office of mayor, calling for openness and accountability.
Other possible high-profile contenders for the job include NDP MP Olivia Chow, former Ontario PC leader John Tory and city councillors Karen Stintz and Denzil Minnan-Wong.
None of them have filed their nomination papers, although Stintz has said she'll run. They have until Sept. 12 to enter the race.
The mayor has steadfastly refused to take a leave of absence or resign since reports surfaced in May of a video that appeared to show him smoking crack.
Police said in October that they had recovered the video but refused to release it and within days, Ford confessed to using the drug while in office.
In November, city council voted to strip him of most of his powers, leaving him with little more than ribbon-cutting duties.
Also on HuffPost