The judge will also hear a defence motion asking that he recuse himself from the trial because his wife works with sexual assault victims.
The judge's wife, Deborah O'Neill, is a psychotherapist at the University of Pennsylvania and coordinates a team that cares and advocates for student sexual assault victims.
The judge said he researched the donation and found it was made by his wife with university funds, not "marital assets".
Cosby's first trial ended in June with a mistrial after the jury failed to reach a unanimous verdict following six days of deliberations.
How many additional accusers - if any - will Montgomery County Judge Steven T. O'Neill allow prosecutors to put before the jury? The defense claims she gave money previous year to a group linked to an organization that's planning to protest outside the retrial.
"They're going to come in and tell their story similar to the victim in question saying listen I was with this man, he used some form of a drug whether it be Quaalude or something else and he had non-consensual sex with me". O'Neill has yet to decide on the request.
O'Neill said Thursday that Cosby's old lawyers raised the prospect of having him step aside in December 2016, but never followed through.
Constand's lawyer has said Jackson is "not telling the truth".
Janice Dickinson Will Testify at Bill Cosby Trial
At Cosby's first trial, which ended in a deadlock, O'Neill allowed only one other accuser to take the stand.
All but one of the 19 women whom prosecutors have identified first came forward publicly either during Constand's 2005 civil suit against Cosby or in 2014, when a parade of more than 50 women appeared nightly on cable news shows to share their own stories of abuse by the comedian. She says when she woke up her pajamas were off and there was semen between her legs.
Pennsylvania's Superior Court on Wednesday rejected an appeal over O'Neill decision not to let Cosby's lawyers immediately challenge his ruling in a higher court.
The accusers, including model Janice Dickinson, were chosen from a group of eight women whose allegations date as far back as the early 1980s.
In every case, she said, Cosby approached them as a mentor figure, later offering them drugs and taking advantage of them when they were powerless to respond.
Cosby's lawyers are in court Thursday in suburban Philadelphia making a last-ditch effort to postpone the comedian's sexual assault retrial after losing their bid to overturn O'Neill's ruling allowing up to five additional accusers to testify.
Prosecutors, who have decried the defence attacks on O'Neill as a "thinly veiled attempt to delay and pollute the jury pool", are looking for the judge to keep out talk of a prior investigation into Constand's allegations and a recent political race where putting Cosby behind bars was at issue.
The case against Cosby was reopened in 2015 after damning deposition testimony in the civil case was unsealed. Though dozens of women have made claims against Cosby only one has resulted in criminal charges.