Militant Aymen Smiri blew himself up on Tuesday evening after security forces surrounded him in the Tunisian capital's Intilaka neighbourhood.
There were no other casualties, officials confirmed.
"Following a long chase, special forces surrounded the terrorist," the interior ministry said in a statement. "When forces began shooting, he blew himself up with an explosive belt he was wearing."
It's the third such incident within a week, which comes months ahead of an election and at the peak of the tourist season.