He was killed in a drone strike on Thursday in North Waziristan, near the border with Afghanistan, the militant group added in a statement.
The TTP has been blamed for dozens of suicide bombings and other attacks.
In December, gunmen from the militant group stormed a college in the Pakistani city of Peshawar, killing at least nine people and injuring 36.
Mehsud s death would further weaken the Pakistani Taliban, who have been forced to reduce their activities due to a relatively successful Pakistan military offensive, BBC Urdu s Haroon Rashid reports.
Pakistani officials claim many TTP militants have been forced to take refuge in Afghanistan as a result, our correspondent adds.
