Where they met: "The Big Bang Theory"
Johnny Galecki and Kaley Cuoco met on the set of "The Big Bang Theory" in 2007, as reported by People. On screen, their characters Leonard and Penny are love interests, which fuelled their off-screen romance sometime in 2008. In an October 2022 joint interview with Galecki, Cuoco told Vanity Fair, "Johnny and I's relationship, in a way, was mimicking Penny and Leonard. They were always giving each other sh*t, and Johnny and I have a similar relationship—which you do after years of being together."
For the next two years, the pair quietly dated while working on-screen together, but ultimately broke up sometime in 2010. Despite breaking up, Galecki and Cuoco remain close friends, with Galecki revealing to Vanity Fair in the same 2022 interview, "We just have such a bond that I appreciate so much. And I think that's part of our great friendship."