The actress found success after starring as Gabrielle in ABC's Desperate Housewives, which wrapped up its series finale in May.
Speaking at the Monte Carlo Television Festival, the actress noted that Latinos are "still under-represented" but offered suggestions on how that can be improved.
"I think we still have a lot more work to do," Longoria said. "In the United States we're 16% of the population, but we're only maybe 10% represented in television and films, so we're still under-represented.
"That's why it's important for Latinos to tell these stories like For Greater Glory. Devious Maids is another one - it's about four Latina maids.
"It's important for us to support those shows as Latinos - to stop being a big number and start being a market and to aggregate our audience.
"The African American community does it really well in the US - any time there's a movie out people really get behind it and support it, so the Latino community has to do that."
Longoria went on to say: "Latinos are a very factioned group in America - there's Mexicans, there's Cubans, there's Puerto Ricans, there's Central Americans, so it's very different.
"Everyone has a different view of what they want to watch and how they want to watch it - in Spanish, in English. But yeah, I think it's [getting better].
"I think the only way to increase it is to get behind the camera - you have to write it, direct it, produce it if you want to see it come into production. I think it's happening more and more."
For Greater Glory: The True Story of Cristiada, which is now playing in the US, is based on the real-life events of the Cristero War in Mexico from 1926-1929.
Longoria also revealed that Marc Cherry's Devious Maids, where she serves as an executive producer, "may be going to Lifetime".
Watch the trailer of For Greater Glory: The True Story of Cristiada below: