The school board — the province's largest — announced the planned walkout on Twitter and its website on Thursday afternoon.
The TDSB says it's awaiting official notification from the union and will announce its plans as soon as information becomes available.
A letter explaining the current situation regarding the elementary teachers was sent home with all elementary and junior high school students earlier this week.
The Toronto teachers have been in a legal strike position since Dec. 10, and teachers have not been participating in field trips, play days or voluntary and extra-curricular activities.
The Elementary Teachers' Federation of Ontario has not yet confirmed that the teachers with the Toronto board will strike on Dec. 18 to show their opposition to Bill 115, but says it will give 72-hours notice of any strike.
The union maintains it is trying to roll back the new anti-strike law that gives the government the power to impose a new collective agreement.
If teachers don't reach local deals with their school boards by Dec. 31, the province will impose one that will freeze the wages of most instructors and cut their benefits, such as the number of sick days they're allowed to take each year.
The governing Liberals have said they will not intervene while the walkouts are kept to one-day protests.
Premier Dalton McGuinty rebuked the union leaders earlier this week for launching the walkouts, forcing parents to scramble for child care.
Also on HuffPost