As temperatures in New York City soared on Wednesday, the musician, 31, and Sansone stepped out together in the trendy Tribeca neighborhood.
Dressed in white, Sansone's sundress proved a necessity as temperatures topped 91 degrees. Puth kept things classic in ripped shorts.
The couple strolled through Tribeca, with Puth holding a can while Sansone held onto his sunglasses.
The "Light Switch" singer and Sansone made their red-carpet debut in February when they stepped out together at Clive Davis' Pre-Grammy Gala in Beverly Hills.
Before that event, Puth marked his 31st birthday in December by sharing pictures taken in a photo booth with Sansone, a family friend.
"???? Ohhhhh I'm NOT a loser…'cause I didn't lose her!!! ???? (Happy birthday to me.)," Puth captioned the post.
Sansone, a digital marketing and PR coordinator for a design consultancy, per her LinkedIn profile, also runs an Instagram account featuring curated outfits. She shared the same image of the two on her own Instagram Story in December, along with the caption "birthday boy" and a heart emoji.
The two had been interacting online for several months, and were seen together at Global Citizen Festival in New York City along with Puth's family members in September 2022. Sansone also shared an Instagram Story of her and Puth smiling at a gathering during the summer of 2022.
Puth previously spoke to Sansone on Instagram Live in 2019, when he asked her about New Jersey, where he was born and raised, and referred to her as "Brookie."
During an appearance on SiriusXM's The Howard Stern Show in October 2022, Puth confirmed that he was in love and was "with somebody" whom he has a shared history with.
"[She's] someone that I grew up with," he admitted, noting that it's "nice" to have someone he's known for a "long time" by his side, considering the volatility of his career.
"She's always been very, very nice to me," Puth told Howard Stern. "I would assume that when times inevitably are hard in the future — because what is life without valleys and peaks — she would be there for me as well."
During the interview, Puth opened up about why they work so well while not revealing his partner's identity.
"Honestly, I get so scared of people now, like, I can't really walk anywhere for whatever reason, and I think the more that happens, the more I just want to retreat to someone that I've known for a long time," he said of the relationship. "I'm not really interested in going out like I used to and being crazy."