Hayden Panettiere Remembered by Courteney Cox as Fun, Happy and Smart

Courteney Cox is remembering her late "Scream" costar Hayden Panettiere ... recalling the fun they had together before Hayden's shocking death last month.

Courteney spoke with Entertainment Weekly at the Toronto International Film Festival, where she was promoting her new movie "Evil Genius," and had nothing but love for Hayden.

Courteney called Hayden a "really wonderful actor" and said the last time they worked together, they had a great time ... remembering her as fun, happy and smart.

She added Hayden's death is "really sad" and "obviously horrible."

The two shared the screen in 2011's "Scream 4" and reunited years later for 2023's "Scream VI" ... with Hayden reprising her fan-favorite role as Kirby Reed.

As TMZ previously reported, Hayden died August 16 at just 36 years old after she was found unresponsive inside a South Carolina residence. Paramedics tried to revive her, but she was pronounced dead at the scene.

TMZ later reported Narcan was found inside the apartment ... and dispatch audio referenced a possible overdose. Hayden's autopsy showed no signs of trauma, while her official cause and manner of death remain pending toxicology results.