"We are seeing people stand in solidarity and seeing communities together and to uplift. And you are going to be part of this movement. I know that this is not that graduation that you envisioned, and this is not the celebration that you imagined," Megan said in the video.
"Now you get to be part of the rebuilding ... and we are going to rebuild and rebuild and rebuild until it is rebuilt. Because when the foundation is broken, so are we.
"You are going to lead with love, you are going to lead with compassion you are going to use your voice. You are going to use your voice in a stronger way that you've ever will do. Because most of you are turning 18 so you are going to vote.
"You are gong to have empathy for those who don't see the world through the same lens as you do because it is diverse, and vibrant and open minded as I know the teachings at Immaculate Heart are. I know that Black lives Matter.
"So I am already excited for what you are going to do in the world. You are equipped, you are ready, we need you and you are prepared. I am so proud to call each of you a fellow alumni and I am so eager to see what each of you do."
Meghan's passionate speech comes just a day after an unearthed video of the Duchess speaking out about racism back in 2012 went viral online.
In the clip, filmed years before the former Suits actress met Prince Harry, Meghan spoke about the racist treatment she received as a biracial woman.
"For me, I think it hits a really personal note. I'm bi-racial, most people can't tell what I'm mixed with and so much of my life has felt like being a fly on the wall. And so some of the slurs that I've heard or the really offensive jokes, or the names, it's just hit me in a really strong way," Meghan explained in the video.
"And then, you know, a couple of years ago I heard someone call my mum the N word. So I think for me, beyond being personally affected by racism, just to see the landscape of what our country is like right now, and certainly the world, and to want things to be better."
Meghan went on to explain how she is often treated differently because people aren't able to identify her racial background.
"Quite honestly, your race is part of what defines you. I think what shifts things is that the world really treats you based on how you look.
"Certain people don't look at me and see me as a black woman or a biracial woman. They treat me differently, I think, than they would if they knew what I was mixed with, and I think that that is ... I don't know, it can be struggle as much as it can be a good thing depending on the people that you're dealing with."
It's understood some of the racist treatment Meghan received at the hands of the British press was one of the reasons behind her and Prince Harry's decision to step back as senior members of the royal family in March.
It's a battle the couple have been fighting for years, throughout their entire relationship.
Back in 2016, when the pair first started dating, Harry released an extraordinary statement via a spokesperson, defending Meghan.
"His girlfriend Meghan Markle, has been subject to a wave of abuse and harassment ... the smear on the front page of a national newspaper, the racial undertones of comment pieces' and the outright sexism and racism of social media trolls and web article comments," the statement said.
"Prince Harry is worried about Ms. Markle's safety and is deeply disappointed that he has not been able to protect her ... This is not a game - it is her life and his."
Race riots continue to sweep the US this week as thousands of protesters turned out across the nation to voice their anger at several African American deaths at the hands of police officers.