After Ellis's graduation from Russell Sage College in 1993 with a degree in Sociology and minor in Women's Studies, she began her career in media through the re-launch of Condé Nast's House & Garden.

[1] In January 2014, Ellis was appointed president and CEO of GLAAD, the largest U.S. lesbian, gay, bisexual, and transgender (LGBT) media advocacy organization.

Following her tenure at In Style, Ellis launched and directed the turnaround of Real Simple, which led her to Vogue where she oversaw ten lifestyle group brands.

On January 1, 2014, Ellis began as president and CEO of GLAAD,[5] the only U.S. organization working to move lesbian, gay, bisexual and transgender (LGBT) equality forward through the power of the media.

In an article in the New York Daily News,[6] Ellis wrote about her Irish-American heritage and sexual orientation, calling on parade organizers to end the ban.

[13] Together, Ellis and Henderson have co-authored a memoir titled Times Two, Two Women in Love and the Happy Family They Made, released in 2011.