Hayden Panettiere planned to see her “Nashville” co-stars in South Carolina and her daughter in Europe to celebrate her upcoming 37th birthday before her tragic death.

Panettiere’s former “Nashville” co-star Sylvia Jefferies exclusively told Page Six they had planned to attend castmate Charles Esten’s August 14 show in Greenville, South Carolina at The Foundry after reconnecting in June over her memoir “This Is Me: A Reckoning.”

“We were going to try to surprise him because it was my birthday and then her birthday, of course, is on Friday. … But that didn’t happen,” Jefferies, who played Panettiere’s character Juliette Barnes’ mom Jolene Barnes on the ABC drama, said.

She continued of her co-stars, who endearingly called her “mama,” “I told her that [Esten] was gonna be there. She’s like, ‘Oh, mama, that sounds like so much fun. Let me see what I can do.’

“And just for [Esten] and I to know that she was right here. It just kind of tears you up. … It just was devastating.”

Jefferies said she was “so happy” to be able to “reconnect” with Panettiere, as she was “in such a different space” while promoting her memoir.

Panettiere died of a suspected overdose on Sunday, August 17 in an Airbnb at the Judson Mill Lofts apartment complex — just a minute from Esten’s set. She was 36.

The “Bring It On: All Or Nothing” star’s on-again, off-again boyfriend Brian Hickerson and his brother, Zach, were at the apartment at the time of her death.

Jefferies told Page Six of Panettiere’s relationship with Hickerson, “Knowing that she was tentatively going to be here when in my perspective, it’s probably not the best choice for her to be here and where she was and who she was with.

“I knew this human, this person, this horrible human being lives in South Carolina and I thought oh why are you … okay whatever it wasn’t my business.”

As Page Six exclusively reported, Panettiere also planned to travel to Europe to see her daughter Kaya, 11, who she shares with her ex-fiance, Wladimir Klitschko.

“She was planning on spending the week of her birthday visiting her daughter in Germany,” a source close to Panettiere told Page Six. “She was so excited to see her and was telling everyone how much she was looking forward to spending time with her.”

Page Six previously reported Panettiere made plans to see her daughter — and can now reveal the trip was for the actress’ birthday.

Panettiere would have turned 37 today.

Klitschko, 50, took to social media on Friday to share a touching birthday message dedicated to the late actress.

“Today is Hayden’s birthday. Instead of celebrating the way we had planned, today we celebrate her life, her spirit, and the love she brought into this world,” Klitschko wrote on Instagram.

“I want to thank all of Hayden’s fans, friends, and everyone who has reached out for the incredible outpouring of love and support,” he continued. “At a time filled with so much sadness, your kindness has reminded me that there is still so much good in humanity.”

He ended his post by enouraging his fans to reconnect with friends and show kindness.

“Love is a superpower. Use it,” he wrote. “Happy Birthday, Hayden. ❤️ You are loved, you are missed, and you will never be forgotten.”

On Sunday, authorities responded to a South Carolina Airbnb for a suspected “overdose.”

The coroner is awaiting toxicology results to determine cause and manner of death.