Former Australia captain David Pocock has called time on his 15-year rugby career.

Pocock retired from international duty following the 2019 World Cup, having earned 78 caps for his country.

And now the 32-year-old is stepping away from the game altogether, opting out of the final year of his contract at Japanese side Panasonic Wild Knights.

"While it was a tough decision, it really feels like the right one now and as a lot of former athletes talk about, it's not going to be smooth sailing but it's going to be a great challenge," Pocock told Rugby Australia.

Pocock, who also represented the Western Force and the Brumbies, steps away from the game with some self-confessed regrets.

He featured in three World Cups for the Wallabies but never got to lift the trophy, with his last attempt halted in a 40-16 quarter-final thrashing at the hands of England.

"On the day, we were fairly soundly beaten by a pretty good English team," he said.

"It certainly does [haunt you]. You wonder if you were on the other side of the draw, not losing that game to Wales (29-25), but that's sport.

"That's the great thing about sport - you get an opportunity and if you're not the most deserving on the day then that's what history records."