Elliott was born in Washington, D.C. to a Chilean mother and an American father. She studied comparative literature at Occidental College, where she developed an interest in documentary film. In 1995, Elliott worked in Chile and Argentina as a field producer for "La Tierra en que Vivimos," a natural history television program. She then moved to San Francisco to co-direct and write the documentary "It's All Good," exploring the subculture of aggressive inline skaters in Los Angeles and New York City. In 1999, Elliott attended Columbia University's Graduate School of Journalism, graduating first in her class.
Elliott joined The Miami Herald as a reporter in 2000, covering crime, courts, immigration and Latin American politics. She left The Miami Herald for The New York Times in May 2003. As a metro reporter for The Times, she covered the Bronx and then created her own beat - Islam in a post-9/11 America - writing extensively about the backlash against Muslims after the September 11 attacks, domestic radicalization and militant jihad.
In December 2013, Elliott published "Invisible Child," a 28,000-word, five-part series for the Times on child homelessness in New York City. Elliott is currently expanding the series into a book for Random House as an Emerson Fellow at New America Foundation.
In 2007, Elliott received the Pulitzer Prize for Feature Writing for a series of articles on Sheik Reda Shata, an Egyptian-born imam living in Brooklyn.
Elliott is also the recipient of the George Polk Award, the Scripps Howard Award, the David Aronson Award and prizes by the Overseas Press Club, the American Society of Newspaper Editors, the Society of Professional Journalists and the New York Press Club. Her work has been featured in the collections “Best Newspaper Writing” and “Islam for Journalists: A Primer on Covering Muslim American Communities in America.”
In May 2014, Elliott received an honorary doctorate from Niagara University, which cited her “courage, perseverance, and a commitment to fairness for those without a public voice rarely demonstrated among writers today.”
In May 2015, Elliott was awarded Columbia University's Medal for Excellence, awarded to one alumna under 45 every year.