In 2014, Sharma played a television journalist who befriends an alien (played by Aamir Khan), in Rajkumar Hirani's religious satire PK. Critic Saibal Chatterjee wrote that Sharma plays "a feisty poetry-loving girl who knows her mind far more than most Hindi film heroines are allowed to" and praised her for "hold[ing] her own" against Khan. Critically acclaimed, PK emerged as the highest-grossing Bollywood film with a worldwide revenue of over ₹7 billion (US$98 million). Sharma launched a production company named Clean Slate Filmz, whose first release was Navdeep Singh's thriller NH10 (2015), in which she also played the lead role. Screened at the 5th Beijing International Film Festival, it tells the story of a married couple whose lives are endangered after an encounter with a group of criminals. In preparation, Sharma underwent interval training for three months to build her stamina. Saibal Chatterjee found the film to be a "taut and riveting thriller" and praised Sharma for "conveying a range of moods as she moves from the vulnerable to the fearless in a battle in which the odds are stacked heavily against her", and Prarthana Sarkar of International Business Times credited her for breaking away from her romantic comedy image. The film also emerged as a box office success.
In Anurag Kashyap's period crime drama Bombay Velvet (2015), (based on the historian Gyan Prakash's book Mumbai Fables) co-starring Ranbir Kapoor and Karan Johar, Sharma was cast as a jazz singer, Rosie Noronha. Her character was referenced from the actresses Brigitte Bardot, Helen and Waheeda Rehman. To prepare, Sharma watched films of the 1950s and 1960s, and documentaries about hair and make-up. She also used temporary lip enhancers for the part, citing it as the reason behind her changed appearance on a chat show in 2014, and refuted media speculation about having undergone plastic surgery. Bombay Velvet was screened at the Locarno and Bucheon film festivals; critical opinion was mixed. Writing for Business Standard, Ritika Bhatia praised Sharma's performance in the song "Dhadaam Dhadaam": "she fills the stage with such raw emotion that her mascara-laden tears and fake eyelashes flutter with arresting passion". However, the film failed to recoup its ₹1.2 billion (US$17 million) investment. In the same year, Sharma featured in the supporting role of a dancer aboard a cruise ship in Zoya Akhtar's Dil Dhadakne Do, an ensemble comedy-drama in which she was featured opposite Ranveer Singh. The song sequence "Pehli Baar" was choreographed by her and Singh; Shilpa Jamkhandikar of Reuters praised their on-screen chemistry and described it as "crackling". Her performances in NH10 and Dil Dhadakne Do earned Sharma Filmfare Award nominations for Best Actress and Best Supporting Actress, respectively.
Sharma has also spoken up for animal rights on social media. In April 2014, she took to Twitter to ask for a ban on horse-drawn carriages in Mumbai. In June 2015, she condemned the Yulin Dog Meat Festival in China, and urged her fans to sign an online petition aimed at stopping it. In October 2015, she launched 'Pawsitivity', a campaign aimed at sensitising people about the adverse effects of noise, air, water and soil pollution on animals. In October 2017, Sharma launched her own clothing line, named Nush.