Rumors of a possible romance between the actors Sydney Sweeney and Glen Powell swirled online this week after a series of seemingly flirtatious moments catapulted them into the spotlight. The two have been filming their upcoming romantic comedy “Anyone But You” in Australia, and fans have been following along as they post affectionate photos on Instagram and paparazzi photograph them on set.

The public interest in Ms. Sweeney and Mr. Powell may be heightened because they’re both romantically linked to other people. Ms. Sweeney, best known for her roles in “Euphoria” and “White Lotus,” is engaged to Jonathan Davino, a restaurateur, but has rarely publicly discussed her relationship. “I don’t date people in the spotlight,” she told Cosmopolitan last year. Mr. Powell, who starred in “Top Gun: Maverick,” was reported to be dating the model Gigi Paris. But some fans believed Ms. Paris had suggested that they were no longer together when this week she posted an Instagram video of herself walking down a city street with the caption, “know your worth & onto the next.”

There’s plenty of precedent when it comes to celebrities falling for each other on set, including Eva Mendes and Ryan Gosling on “The Place Beyond the Pines,” Blake Lively and Ryan Reynolds on “Green Lantern,” Penélope Cruz and Javier Bardem on “Vicky Cristina Barcelona” and Vanessa Hudgens and Zac Efron in “High School Musical,” to name a few.

Whether there’s anything real between these actors, we’ve seen this before: the power of relationship rumors create buzz around a film and elevate the profiles of the celebrities involved.

Olivia Wilde and Harry Styles: ‘Don’t Worry Darling’

Just last year, the press tour around the film starring Harry Styles, Florence Pugh and Chris Pines, directed by Olivia Wilde, at times overshadowed the film itself. After Ms. Wilde cast Mr. Styles, she and her longtime partner Jason Sudeikis split, and the director was photographed holding hands with the pop star, spurring dating rumors that were revealed to be true. When asked about her relationship with Mr. Styles by Variety last year, she said, “We both go out of our way to protect our relationship; I think it’s out of experience, but also just out of deep love.” The couple’s romance was public until rumors of their breakup started swirling around the same time as the movie’s release. But it still did well at the box office: According to Box Office Mojo, the film earned more than $87.6 million worldwide.

Bradley Cooper and Lady Gaga: ‘A Star Is Born’

Both stars were with other people at the time Mr. Cooper was directing Lady Gaga in the Oscar-nominated film. She was engaged to Christian Carino, and Mr. Cooper was with the model Irina Shayk. That didn’t stop people from believing that the co-stars’ spark translated beyond the cameras. The film made more than $436 million in theaters and was nominated for eight Academy Awards. Lady Gaga won best original song for “Shallow,” which the duo sang together at the Oscars, a performance that convinced viewers further that the two were more than just colleagues. Mr. Cooper talked about the buzzy Oscars performance with the Hollywood Reporter in 2021, saying their intention was to act as if they were their characters: “They kind of fall in love in that scene in the film. It’s that explosive moment that happens to happen to them on a stage in front of thousands of people. … It would have been so weird if we were both on stools facing the audience.” Lady Gaga broke up with her fiancé that same month, and Mr. Cooper ended his relationship a few months later. But years following their rumored romance, both have stood firm that it was just acting.

Brad Pitt and Angelina Jolie: ‘Mr. and Mrs. Smith’

Brad Pitt was married to Jennifer Aniston while filming “Mr. and Mrs. Smith,” and the public saw them as a Hollywood power couple. But they also saw a tangible chemistry between Mr. Pitt and Ms. Jolie. Rumors about the co-stars started to pop up in tabloids, and by January 2005, Ms. Aniston and Mr. Pitt had announced their separation after five years of marriage. It didn’t take long for the new couple to go public with their relationship, appearing in a photo spread in W magazine titled “Domestic Bliss: Angelina Jolie and Brad Pitt at Home” that July. But it wasn’t until years later that they finally admitted to falling in love on the set of “Mr. and Mrs. Smith.” The film was a huge commercial success, earning $487 million at the box office. They later got married in 2014, and ultimately divorced in 2016.

Ben Affleck and Jennifer Lopez: ‘Gigli’

Last year, Ms. Lopez told Apple Music 1 that she and Mr. Affleck realized they “were crazy about each other” when they filmed “Gigli,” a 2003 rom-com in which they played love interests. At the time, she was engaged to the dancer Cris Judd, but shortly after they broke up, Ms. Lopez and Mr. Affleck got together, and the term “Bennifer” became part of the pop culture lexicon. “Gigli” was panned by critics, was largely considered one of the worst movies of all time and barely made more than $7 million while costing $75 million to make. What was going on between these two offscreen was more interesting — a fast-track romance that led to an engagement in November 2002. The pair may have not proven to be big at the box office, but they have had a formidable on-again-off-again reign as a tabloid “It” couple. Last July, Bennifer finally tied the knot.