Stokes has not been bowling regularly because of the injury but expects to return in time for England's five-test tour of India, which begins on January 25.
"I'll be fine for the test series in India. But yes, I am having surgery after the World Cup," Stokes told reporters ahead of Saturday's World Cup game against Australia in Ahmedabad.
"Not bowling makes it seem a lot longer than what it normally is. But over the last 18 months, it's been 'will I, won't I?'
"It's probably the first time since I've had this knee issue where it's been quite clear that I'm not going to be bowling."
England have had a World Cup campaign to forget in India as the defending champions sit bottom of the standings with only one win in six games.
They also have the worst net run rate, making qualification for the semi-finals next to impossible unless they win the rest of their games convincingly and hope other results go their way.
"We've had a disastrous World Cup and there's no point sugar-coating that because it's the truth. But we know these last three games, for us, we've got a lot to play for," Stokes said.
"I think the biggest thing that we've got to play for is obviously the pride of what it is to put the Three Lions on your chest, walking out on to the field every time is a very special occasion and something that we value very highly."
When asked why England had underperformed at the tournament, Stokes said they failed to take control of games but apart from that the team could not quite put a finger on what went wrong.
"The problem is that we've been crap..." Stokes added. Every opportunity that we've had in front of us where we feel like we can take control of the game, the opposition's managed to get it back towards them.
"We've been nowhere near good enough to be able to compete in a World Cup, which has been incredibly disappointing because we know we're so, so much better than what we've shown out here.
"If we knew what had gone wrong, we would have been able to fix it. But unfortunately, we don't. It's one of those tournaments where it's just been a disaster."
