Howard attended Stagedoor Manor, a performing arts camp in upstate New York, with actress Natalie Portman. After attending Greenwich Country Day School until 1996 and then graduating from Byram Hills High School in 1999, Howard studied at New York University’s (NYU) Tisch School of the Arts for three years, during which time she also attended the Stella Adler Conservatory, The Experimental Wing, and International Theatre Wing in Amsterdam. During her schooling, she took part in the concept recording of the Broadway-bound musical A Tale of Two Cities. She left New York University without completing her degree. Decades later, she returned and completed her degree in 2020.

Howard met actor Seth Gabel at New York University, and the two dated for five years before marrying on June 17, 2006. They had planned to start a family together in their 30s; however, seven days after their wedding, she learned that she was expecting their first child. Howard gave birth to their child, a son named Theodore, nicknamed Theo, in 2007. Howard openly discussed having experienced post-partum depression. With the help of a physician and a therapist she recovered from the depression, which lasted for about 18 months. Howard said of the depression in 2010,

In 2007, Howard starred in her first blockbuster, Spider-Man 3 as Peter Parker’s classmate Gwen Stacy, a fan favorite. A challenge that came with playing Gwen was reminding fans of the good-intentioned character who was Peter’s first love in the comics, yet came off as “the other woman” in the movie. Howard dyed her naturally red hair blonde for the role and performed many of her own stunts, unaware that she was a couple of months pregnant. The film grossed $890 million. Terminator Salvation was her next project. Cast in June 2008, she replaced Claire Danes as Kate Connor. Howard was already a fan of the series. It grossed a total of $370 million, but was not well received critically.

Howard starred as the lead character in The Loss of a Teardrop Diamond in 2009. Based on a 1957 screenplay by Tennessee Williams, it did not play at many theaters. She played the role of Victoria, a vampire seeking revenge, in the Twilight series’ third installment The Twilight Saga: Eclipse. She landed the part after Rachelle Lefevre was dropped due to a scheduling conflict and filming started in August 2009. Howard had already been a huge fan of the books and considered Victoria to be an “incredible character”. Released on June 30, 2010 the film made nearly $700 million and although reviews were mixed, critics gave very positive reviews for Howard in the role.

In December 2009, Howard was cast in Clint Eastwood’s Hereafter (2010), as a burgeoning love interest for Matt Damon’s character.

The couple had a second child, daughter Beatrice, in 2012.

In 2015, Howard appeared in the lead role, alongside Chris Pratt, in the science fiction action film Jurassic World, the fourth film in the series. The film was a commercial and critical success, grossing over $1.672 billion in worldwide receipts. Howard’s performance, as the park’s operations manager Claire Dearing, and on-screen chemistry with Pratt was praised.

In 2016, she starred in the fantasy adventure Pete’s Dragon, a remake of the 1977 film of the same name, and appeared in the crime drama Gold with Matthew McConaughey. That same year, she appeared in “Nosedive”, an episode of the Netflix anthology series Black Mirror.

All of the Howard children were raised away from the world of show business. Their parents did not allow them access to television and instead encouraged outdoor activities and hobbies. At the age of seven, however, she was allowed to be an extra in her father’s movies. In an appearance on Watch What Happens Live with Andy Cohen in 2017, she mentioned that she and her siblings were babysat by family friend Tom Cruise on several occasions. She was raised in Westchester County, New York, and on a farm in Greenwich, Connecticut.

Howard reprised her role as Claire again in Jurassic World: Fallen Kingdom, which was released in 2018. In 2019, she had leading roles in two films, providing the voice of the titular character Bella in A Dog’s Way Home, and appearing as Elton John’s mother in the musical biopic Rocketman, directed by Dexter Fletcher. Also in 2019, she made her feature film directorial debut with the documentary film Dads. It premiered at the 2019 Toronto International Film Festival, where it was named second runner-up for the People’s Choice Award for Documentaries.