Jennifer Lopez, Diego Luna, Ricky Martin, Lin-Manuel Miranda and others were also part of the powerful letter of support, hope but also anger and despair.
"As a Latina, my heart breaks with every attack on our dignity, humanity and lives. And as an American, I fear for the future of my country when our culture and policies lack a basic decency and respect for human life," Ferrera wrote in a press release for the letter.
The mass shooting in Texas earlier this month took the lives of 22 people, with dozens more injured. Separately, nine people were killed in a mass shooting just hours later in Dayton, Ohio.
The alleged gunman in the El Paso shooting cased the store, authorities said, to look for Mexicans to kill before he carried out the attack.
Longoria and others have been outspoken for the need for gun reform in the wake of both mass shootings.
This letter, however, focused on respect and support for the Latino community.
The El Paso shooting took place at a Walmart near the Mexican border.
"We're facing a moral crisis in our country, and we chose to use this moment to raise our voices, and speak up. Integrity starts with looking in the mirror and this letter calls on everyone, not just our community, to choose humanity and decency over hate and violence," Longoria said in the release.
The letter reads as follows:
If you are feeling terrified, heartbroken and defeated by the barrage of attacks on our community, you are not alone.
We have been smeared by political rhetoric and murdered in violent hate crimes. We have been separated from our families and have watched our children caged. We have been targeted with mass shootings and mass ICE raids meant to terrify us, squash our hope, and break our spirits.
But, we will not be broken. We will not be silenced. We will continue to denounce any hateful and inhumane treatment of our community. We will demand dignity and justice.
Though real pain and fear are sweeping through our communities, we remain powerful. The indignities and cruelty we have endured will never change the truth that the contributions we make to this country are invaluable. Our humanity must be respected. And, we won't stop organizing for ourselves, our children, and for the soul of this nation.
To our allies who feel our community's pain, we need you. We cannot make change without your voices and action. We call on you to speak out loudly against hate, to contribute your resources to organizations that support our community, and to hold our leaders accountable.
We ask you to join us in building a better country where we are all safe and valued. May we turn this time of despair into a time of action. May our love for one another be the guiding light in these dark times.
Last week, Longoria appeared on "Strahan & Sara" and delivered a message to her native Texas.
"It's heartbreaking and horrifying every time," the actress and activist said. "I just ask that people don't get numb to it ... We can't stay numb, we have to have action."
"It's definitely a mental health problem," she said, but added that "we need some gun reform."