As a defence lawyer in the 1960s in segregated South Africa, the now-renowned legal expert worked for activists exposing torture and helped establish rights for prisoners on Robben Island.
The notorious jail is synonymous with Nelson Mandela, who was imprisoned there for nearly two decades.
She rose to become the first non-white woman on the country's high court and the first non-white woman to serve as the United Nations Human Rights Commissioner for several years.
In Australia to accept a peace prize and meet Australian diplomats, she tells AAP she sees another apartheid system operating today - worse than the one she grew up in.
"Israel's apartheid is much more brutal than what we experienced," she told AAP.
Dr Pillay chaired an independent UN commission of inquiry that in August concluded Israel was conducting a genocide in the Palestinian territory of Gaza.
The findings of the commission, which included Australian legal expert Chris Sidoti, have been flatly denied by Israel.
But Dr Pillay maintains the Gaza conflict differs from other ongoing wars because of Prime Minister Benjamin Netanyahu's explicit invoking of biblical language and imagery to justify the bombing of the enclave.
"It's ridiculous how they (Israeli leaders) think they've been directed by God himself to carry out these awful crimes," she said.
"We've noted all of that in our reports.
"The sinister part of the conflict in Israel-Gaza, which does not appear in other serious situations in Sudan and the Democratic Republic of Congo is you don't have that level of ... propaganda to convince these soldiers to fight."
She alleged Israel had waged information warfare, whitewashing documented violations at the Gaza "crime scene" and steadily shutting down those "who could report on the truth".
Dr Pillay says Israel has barred her and other UN officials from entering.
Australia and other nations faced being complicit in facilitating serious atrocities, she warned senior Department of Foreign Affairs officials this week.
"Do you realise you're breaking the law, I ask? They say, they're not and they've already now recognised the state of Palestine," she said.
"The worst possible thing is, if you know about it and you keep quiet. Governments can't say we didn't know."
But the sharp, straight-talking octogenarian is not buying it.
Her pivotal work on the ad-hoc court into the Rwanda genocide paved the way for her to serve as a judge on the International Criminal Court.
During her tenure on the Rwanda tribunal, Dr Pillay was instrumental in setting a legal precedent by incorporating sexual violence and rape as a category of genocide.
That followed one of the most confronting moments of her career: building the case that more than 200,000 Tutsi women were systemically targeted and raped by officials of the rival ethic group, the Hutu.
When asked about the leaking of a recent graphic video showing the rape and torture of male Palestinian detainees in an Israeli jail, she urged the Israeli prime minister to punish the perpetrators.
"That's what's terrible about war: it's completely lawless. Nobody's controlling the soldiers."
Mr Netanyahu had dubbed the airing a "public relations disaster" with a top military lawyer fired from her post.
12°C