Ryder's switch to the south was confirmed by the Otago Cricket Association this morning.
The explosive left-hander rejoins former coach Vaughn Johnson in a Volts team that, particularly in the shorter forms of the game, will field an imposing batting line-up.
Ryder's manager, Aaron Klee, said Otago appealed as a new home because of the presence of Johnson and the enthusiasm of Ryder's new team-mates.
''It just feels right. The Otago environment feels like the logical place for Jesse to go,'' he told the Otago Daily Times.
Ryder, who is leaving Wellington after nearly a decade, has not played for the Black Caps since February 2012. He made himself unavailable after a ''deeply stressful and emotional time'' in the spotlight.
In March, he was the victim of an assault that left him in hospital in Christchurch in an induced coma.
Klee said a return to international cricket was hopefully not too far away for Ryder.
''He's going to need to perform, firstly. We all want to see some consistency and stability from him.
''He met with Mike Hesson for a good talk last week. We've maintained communication with the Black Caps right through this hiatus.
''At some point, Jesse needs to get back into international cricket. He just needed some time to sort himself out.
''We're getting close to that point. After what happened in Christchurch, we realised there wasn't much point sitting around. It's time to get back on the horse and get the career charging again.
''All going well, it won't take him that long to get back into international cricket.''
Ryder was making good progress, Klee said. There were a couple of lingering concussion issues, but specialists had advised that was to be expected.
Ryder had been working hard on his fitness and was ''probably in better shape than he was at the end of last season''.
