Phillips was born in Illinois, and grew up in the city of Jacksonville. In the fourth grade, she moved to San Diego, California, where her parents became professors at San Diego State University. After graduating from Helix High School, Phillips earned a bachelor's degree in journalism from University of Southern California. Among her first jobs in broadcasting were the positions of weekend anchor and reporter for WLUK-TV in Green Bay, Wisconsin before moving on to WDSU-TV in New Orleans, Louisiana in 1994. Phillips has also held positions as morning anchor for KAMC-TV in Lubbock, Texas, field producer for CNN-Telemundo’s Washington, D.C. offices and a journalist of the special assignment unit of KCBS-TV in Los Angeles, California. In addition to her regular duties on HLN, Phillips participates in the Brain Tumor Foundation for Children, T.A.P.S. (Tragedy Assistance Program for Survivors), Global Down Syndrome Foundation and Big Brothers Big Sisters of America, which she has been involved with since 1992.
Phillips joined CNN in 1999. During her early years at CNN, Phillips was granted access to U.S. Navy Air Wing CVW-9 in 2001 as they prepared for the war in Afghanistan. In January 2002, Phillips spent about a month in Antarctica to work on a television documentary to be featured on the program CNN Presents. Later in 2002, Phillips produced reports focusing on the U.S. Navy’s reconnaissance missions from the USS Paul Hamilton, the Navy’s Special Operations Command, the Navy SEALs, and Special Warfare Combatant Crewman training, riding in an F-14 Tomcat during an air-to-air combat mission over the Persian Gulf. She has also participated in the Navy’s TOPGUN school, SWAT training, and other police and weapons training.
In 2003, she was an embedded journalist during the 2003 invasion of Iraq, where she reported from the USS Abraham Lincoln. In 2006, Phillips was the last journalist to fly in an F-14 Tomcat before its official retirement from service in the U.S. Navy.
Phillips co-anchored CNN Radio's November 4, 2008 election coverage with Capitol Hill correspondent Lisa Desjardins.
In March 2012, Phillips moved to the 11am Newsroom, and her timeslot was shortened to one hour. However, on 26 June 2012, it was officially announced that she would leave CNN and launch her own show at its sister channel HLN. She has occasionally appeared again as anchor of CNN programming since late 2013: for example, as the host of the 2PM Newsroom on November 8, 2013 and the 10AM Newsroom on December 23, 2013.
In 1997 Phillips was named Reporter of the Year by the Associated Press. She has also won four Emmy Awards, two Edward R. Murrow Awards for investigative reporting, the top documentary award from the Society of Professional Journalists for her coverage of Jena, Louisiana and multiple Golden Microphones.
Previously married, in 2010 Phillips became engaged to Fox News correspondent John Roberts. She gave birth to their twins on March 15, 2011.