DiCicco was born in Los Angeles, California to television and film actor Bobby DiCicco Her family moved to New York City when she was young. In second grade, she was selected by Marlo Thomas to appear on the ABC special Free to Be... A Family. She was also cast by Francis Ford Coppola in The Godfather Part III as an unnamed child. and also had a guest role in Kate and Allie. She had a small role as young Cindy Zagarella in the 1993 film Household Saints. At age 15, she was the Photographer on a cover story for New York magazine about prep school Gangsters, which was published on December 1996.

In 1998, DiCicco appeared in the NBC miniseries Witness to the Mob and in the Disney film In the Nick of Time. Besides her appearances in television and commercials, DiCicco has worked on stage with several repertory companies. In 1999, DiCicco and her co-stars in the Nickelodeon pilot Bus No. 9 were nominated a Young Artist Award, but lost to The Sweetest Gift. She also starred in a miniseries called As Our Schoolbus Turns.

DiCicco attended Newhouse School at Syracuse University, hoping to learn more about production as she had done mostly on-camera work with Nickelodeon. Before heading to college, she met a Newhouse alum and Nickelodeon Producer Mike Pecoriello who offered her an opportunity to be the voice of a developing educational programming network called Noggin. She agreed to do the work while being a student and offered to record promos from Syracuse, She was the voice of Noggin throughout her college years, and graduated in 2002. She was also the voice of Miguzi's Erin on Cartoon Network.

As a voice Actress, DiCicco had lead roles on The Buzz on Maggie, The Emperor's New School, Loonatics Unleashed, and Shuriken School. She had recurring roles on The Replacements, El Tigre: The Adventures of Manny Rivera, American Dragon: Jake Long, Bratz, and All Grown Up!. She co-starred as Shelby in the DreamWorks film Over the Hedge and voiced Gwen on Amy Poehler's television series for Nickelodeon, The Mighty B!. DiCicco was the voice of Master Viper in the Kung Fu Panda short film Secrets of the Furious Five. In 2012, she joined the Cartoon Network show Adventure Time in its third season, where she voiced Flame Princess; the show has now run over seven seasons. She also voiced in Pound Puppies and Gravity Falls. She also voices Lynn and Lucy Loud in the Nickelodeon animated series, The Loud House. She was nominated for a Daytime Emmy in 2008 for her performance as Malina on The Emperor's New School, but lost to Eartha Kitt, who did Yzma in the same series. Currently DiCicco provides the voice of Toby the cactus and the sounds of the mule Clementine on Sheriff Callie's Wild West.