The writer behind the bestselling Wallander series said the action was a good way of trying to achieve a situation where “Palestinians are not treated like second-class citizens in their own country, a sort of Apartheid system.”
About a dozen ships will leave Greece next week taking supplies to Gaza.
Mankell, who was on board a vessel seized by the Israeli army last year, said he would join the operation, known as Freedom Flotilla 2.
“The Gaza blockade is still going on and that’s the reason I’m taking part again, because I’ve got no reason to stop until the blockade ends,” he told AFP.
Israeli forces killed nine Turks on board the Mavi Marmara which was taking aid to Gaza in May 2010.
Speaking about the events, he said: “You can never use the word success when people are murdered, you can’t do that.
“But what you can say is that it had an enormous impact.
“Everyone on the planet knows what is really going on in Israel and Gaza, how the Palestinians are treated,” the author said.
“So it really, in a way, changed the world, because no one can say any longer they didn’t know about this.”
Mankell said he believed the latest operation would force politicians to respond.