She added on Twitter: "Her words illustrate the pain and cruelty she's experienced.
"I know first hand the sexism and racism institutions and the media use to vilify women and people of colour to minimise us, to break us down and demonise us.
"We must recognise our obligation to decry malicious, unfounded gossip and tabloid journalism. The mental health consequences of systemic oppression and victimisation are devastating, isolating and all too often lethal.
"I want Meghan's daughter, my daughter and your daughter to live in a society that is driven by respect.
"Keep in your memory the fruitage of the spirit is love, joy, peace, long-suffering, kindness, goodness, faith, mildness, self-control. Against such things there is no law."
British broadcaster Piers Morgan criticised the interview, saying it was "an absolutely disgraceful betrayal of the Queen and the royal family."
American actor and Writer Leslie Jordan posted a video to Instagram that personally told Meghan "the gays have got your back".
The daughter of civil rights activist, Martin Luther King Jr, Bernice King, commented on the allegations of racism discussed during the interview.
Perhaps the most shocking revelation of the whole interview came when discussing baby Archie.
Meghan revealed that, when she was pregnant, the royal family changed the protocols and told them their unborn child would not become a prince or princess and would not have any security.
She also said members of the royal family had a conversation with Harry about "how brown" Archie's skin would be.
When Harry joined the interview, Oprah asked him about that conversation. He says he was "shocked" and refused to elaborate.
Meena Harris, the niece of Vice President Kamala Harris also spoke up, tweeting ahead of the interview to celebrate "Meghan Markle appreciation day".
She regularly tweeted while viewing the interview.
Poet and activist Amanda Gorman, who read her piece The Hill We Climb at the inauguration of US President Joe Biden said Meghan was "the Crown's greatest opportunity for change, regeneration and reconciliation in a new era".
Actress and talk show host Jada Pinkett-Smith took to Instagram the tease the wild possibility of the Queen speaking on her Facebook Watch talk show Red Table Talk.
• CBS presents Oprah with Meghan and Harry will broadcast on Three on Tuesday, March 9, at 7.30pm.
