Wearing a blue jail uniform, Simpson, 65, walked into the courtroom flanked by guards and raised his eyebrows to acknowledge people he recognized.
The former football star and a new set of lawyers are hoping to convince a judge that Simpson's trial lawyer, Yale Galanter, shouldn't have handled Simpson's case because he had conflicted interests. Simpson claims it was Galanter who gave his plan the "green light" to confront two men selling Simpson-related sports items.
"He had given prior advice to O.J. Simpson regarding how to get back his stuff, and that advice was never part of the trial," said ABC News legal analyst Dana Cole.
Simpson is serving nine to 33 years in a Nevada prison.
According to Simpson's new lawyers, Galanter was paid nearly $700,000 for Simpson's defense but had a personal interest in preventing himself from being identified as a witness to the crimes. Simpson also says Galanter never told him a plea deal was on the table.
Simpson was infamously acquitted in a criminal trial of the 1994 murders of his ex-wife Nicole Brown Simpson and her friend Ron Goldman. Simpson never took the stand then or at this robbery trial, but on Wednesday, Simpson is scheduled to take the stand. Galanter is expected to testify Friday.
The five-day proceedings are technically neither a trial nor appeal. There won't be any opening statements. The judge will listen to testimony before deciding whether Simpson deserves a new trial.
The Associated Press contributed to this report.