Singer Lesley Gore in 1966. (Dan Grossi/AP)

Lesley Gore, a singer-songwriter who topped the charts in 1963 at age 16 with her epic song of teenage angst, “It’s My Party,” and followed it up with the hits “Judy’s Turn to Cry” and the feminist anthem “You Don’t Own Me,” died Feb. 16 at a hospital in Manhattan. She was 68.

The cause was lung cancer, said her partner of 33 years, Lois Sasson.

Lesley Gore was born Lesley Sue Goldstein on May 2, 1946, in Brooklyn and grew up in Tenafly, N.J. She took professional voice lessons from an early age, was signed to Mercury Records after its president spotted her singing at a hotel, and was guided at Mercury by Quincy Jones.

Her hits included “She’s a Fool,” “Sunshine, Lollipops and Rainbows,” “That’s the Way Boys Are” and “Maybe I Know.” She also played Catwoman’s sidekick in the TV comedy “Batman” in the 1960s.

As her career grew, Ms. Gore decided to complete her education and, at 18, she enrolled at Sarah Lawrence College in Bronxville, N.Y.

Gore in 2008. (Louis Lanzano/AP)

“The record company wasn’t thrilled, my agent wasn’t thrilled — but I sensed very early just how fickle this business is,” she told the Sacramento Bee in 2006. “I had a good brain in my head and I saw it as an opportunity to cloister myself.”

By the time she graduated, in 1968, musical tastes had changed considerably. Her last Top 20 hit was “California Nights” in 1967.

She co-wrote with her brother, Michael, the Academy Award-nominated “Out Here On My Own” from the 1980 film “Fame.” In the 1990s, Ms. Gore co-wrote “My Secret Love” for Allison Anders’s film “Grace of My Heart.”

A couple of years later, she appeared in “Smokey Joe’s Cafe” on Broadway. Ms. Gore had been working on a stage version of her life with playwright Mark Hampton when she died.

In 2005, she released “Ever Since,” her first album in 30 years, but was sure to revisit older hits in front of fans. “If I’ve learned anything in this business,” she told the New York Times that year, “how stupid would it be not to do ‘It’s My Party’ when people come to hear it?”

She officially came out to the public when she hosted several episodes of the PBS series “In the Life,” which dealt with gay and lesbian issues.

During the 2012 presidential campaign, Ms. Gore turned “You Don’t Own Me” into an online video public service announcement demanding reproductive rights. It starred Lena Dunham and Tavi Gevinson, among others.

In the past few years, she performed at Feinstein’s at the Loews Regency in New York and, along with Ronnie Spector and LaLa Brooks, headlined the “She’s Got the Power” concert outdoors at Lincoln Center in 2012.

In addition to Sasson, Ms. Gore is survived by her brother and mother, Ronny.