The emerging Blues star is having a career-best season to emerge as an All Australian contender for the first time.
His current four-year deal is due to expire at the end of 2022, although the Blues have moved quickly to lock him in for another four years.
It will tie him to the Blues until at least the end of 2025.
The signature of Weitering is the first major move made by new list boss Nick Austin as the club prioritises the 22-year-old.
Joining the club earlier this year, Austin is leading the Blues’ list management team alongside Michael Agresta who is Carlton’s national recruiting manager.
Weitering’s deal is a big win for the club, while a number of other key Blues are set to come out of contract at the end of next year.
— Carlton FC (@CarltonFC) August 13, 2020