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.

Trump says US could restart Iran strikes 'if they misbehave'
Israeli military urge southern Lebanon residents to evacuate
Russia's Primorsk port hit as Ukraine launches wave of drone strikes
Israel court extends detention of Gaza flotilla activists
At least six dead, thousands displaced as heavy rains hit northeastern Brazil