It was her first solo public appearance since she resumed the role of US first lady on January 20.
The first lady said it was "heartbreaking" to see teenagers and especially girls grapple with the fallout after they become the targets of malicious and sexually explicit online content. She called on Congress to prioritise the wellbeing of young people.
"This toxic environment can be severely damaging. We must prioritise their well-being by equipping them with the support and tools necessary to navigate this hostile digital landscape," she said during a roundtable discussion about the "Take It Down Act" at the US Capitol.
"Every young person deserves a safe online space to express themself freely, without the looming threat of exploitation or harm," she said.
The Take It Down Act, sponsored by Republican senator Ted Cruz and and Democrat senator Amy Klobuchar, passed the Senate in February.
Melania Trump's public support for the legislation could help get it through the Republican-controlled House and to President Donald Trump's desk to become law.
Cruz was among the lawmakers who joined the first lady for the discussion in the Capitol's Mansfield Room. Online safety advocates and survivors of non-consensual intimate imagery also participated.
Cruz said on Monday on social media that the measure was inspired by Elliston Berry and her mother, who visited his office after Snapchat refused for nearly a year to remove an AI-generated non-consensual graphic image, also known as a "deepfake".
"No one should have to experience the pain, humiliation, and trauma that so many Americans have at the hands of AI deepfakes," Cruz said.
Meta, which owns and operates Facebook and Instagram, supports the legislation.
The bill would make it a federal crime to knowingly publish or threaten to publish intimate imagery online without an individual's consent, including realistic, computer-generated intimate images of people who can be identified.
If the bill becomes law, social media platforms would be required to remove such images within 48 hours of a victim's request and take steps to delete duplicate content.
"Having an intimate image - real or AI-generated - shared without consent can be devastating and Meta developed and backs many efforts to help prevent it," Meta communications director Andy Stone said on X.
In the first Trump administration, Melania Trump led a youth initiative she called Be Best, which included a focus on online safety. She has said she's interested in reviving the program.
