Grande released her second studio album My Everything on August 25, 2014 and debuted atop the Billboard 200. Its lead single "Problem" features Australian rapper Iggy Azalea and premiered at the 2014 Radio Disney Music Awards on April 27, 2014. The song debuted at number three (eventually climbing to number two) on the Billboard Hot 100, and debuted at number one on the UK Singles Chart, becoming Grande's first number one single in the United Kingdom. The album's second single, "Break Free", featuring German musician and producer Zedd, peaked at number four in the United States. She performed the song as the opening of the 2014 MTV Video Music Awards, and won Best Pop Video for "Problem". Grande and Nicki Minaj provided guest vocals on "Bang Bang", the lead single from Jessie J's album Sweet Talker, which peaked at number one in the UK and reached number three in the US. With the singles "Problem", "Break Free", and "Bang Bang", Grande joined Adele as the only female artist with three top ten singles simultaneously on the Billboard Hot 100 as a lead artist.
Grande was the musical performer on Saturday Night Live, with Chris Pratt as the host on September 27, 2014. That same month, third single from My Everything, "Love Me Harder", featuring Canadian recording artist The Weeknd, was released and peaked at number seven in the United States. The song became her fourth top ten single of 2014, the most by any artist that year. In November 2014, Grande was featured in Major Lazer's song "All My Love" from the soundtrack album for the film The Hunger Games: Mockingjay – Part 1 (2014). The same month, Grande released a Christmas song titled "Santa Tell Me" as a single from the reissue of her first Christmas EP, Christmas Kisses (2014). She later released the fifth and the final single from My Everything, "One Last Time", which peaked at number 13 in the US.
Grande is a light lyric soprano, possessing a four-octave vocal range and a whistle register. With the release of Yours Truly, critics compared Grande to Mariah Carey because of her wide vocal range, sound and musical material. Julianne Escobedo Shepherd of Billboard wrote that both Carey and Grande have "the talent to let their vocals do the talking ... that's not where the similarities end. ... Grande is subverting it with cute, comfortable, and on-trend dresses with a feminine slant." Grande responded to the comparisons, "[I]t's a huge compliment, but when you hear my entire album, you'll see that Mariah's sound is much different than mine." Steven J. Horowitz of Billboard wrote in 2014, "With her sophomore album, the 'Problem' singer no longer resembles [Carey] – and that's okay."
Grande cited Audrey Hepburn as a major style influence in her early years of fame, but began to find emulating Hepburn's style "a little boring" as her career progressed. She also drew inspiration from actresses of the 1950s and 1960s, such as Ann-Margret, Nancy Sinatra and Marilyn Monroe. Grande's modest look early in her career was described as "age appropriate" in comparison to contemporary artists who grew up in the public eye. Jim Farber of New York Daily News wrote in 2014 that Grande received less attention "for how little she wears or how graphically she moves than for how she sings." That year, she abandoned her earlier style and began wearing short skirts and crop tops with knee-high boots in performances and on red carpets. After years of dyeing her hair red for her role as Cat Valentine, Grande wore extensions as her hair recovered from the damage. Anne T. Donahue of MTV News noted that her iconic high ponytail received more attention than her fashion choices.
Although Grande drew criticism for allegedly impolite interactions with reporters and fans in 2014, she dismissed these reports as "weird, inaccurate depictions". Rolling Stone wrote: "Some may cry 'diva', but it's also Grande just taking a stand to not allow others to control her image." In July 2015, Grande was seen on surveillance video in a doughnut shop licking doughnuts that were on display and saying "I hate Americans. I hate America. This is disgusting", referring to a tray of doughnuts. She apologized, writing that she is "extremely proud to be an American" and that her comments related to American obesity. She later released a video apology for "behaving poorly". The incident was parodied by The Muppets and featured in Miley Cyrus' Saturday Night Live cover of "My Way", about the regrets of the summer of 2015. Grande poked fun at the incident herself when hosting Saturday Night Live in 2016, saying: "A lot of kid stars end up doing drugs, or in jail, or pregnant, or get caught licking a doughnut they didn't pay for." In 2020, she revealed that she stopped doing interviews for some time due to the fear of her words being misconstrued and being mislabeled a "diva".
In October 2014, Grande joined the bottled water brand WAT-AAH! as an equity holder and partner. In November 2015, she released a limited edition handbag in collaboration with Coach. In January 2016, she launched a makeup collection with MAC Cosmetics, donating 100% of proceeds to the MAC AIDS Fund. In February 2016, Grande launched a fashion line with Lipsy London. Later that year, she teamed up with Brookstone, using the concept art of artist Wenqing Yan, to design cat ear headphones. In 2017, Grande collaborated with Square Enix to create a character based on herself for the mobile game Final Fantasy Brave Exvius. Grande was a limited time unlockable character as part of the Dangerous Woman Tour event, which also included an orchestral remix of Grande's song "Touch It"; the character, named Dangerous Ariana, is a magical support character who uses music-based attacks. In September 2017, she became a brand ambassador for Reebok. In August 2018, she partnered with American Express for The Sweetener Sessions, a partnership which continued through the Sweetener World Tour in 2019, alongside T-Mobile. In March 2019, she partnered with Starbucks for the launch of the Cloud Macchiato beverage. In May 2019, Grande was announced as the face of Givenchy's Fall-Winter campaign. The campaign began in July and generated $25.13 million in media impact value. Beats, Samsung, Fiat, Reebok, and Guess products have been featured in Grande's music videos. She has appeared in commercials for Macy's, T-Mobile, and Apple, as well as for her own fragrances.