The country singer broke the tragic news on IG Wednesday, writing  "We lost my daddy last night, and I really have no words yet." She didn’t share any details of the circumstances surrounding his death.

Lauren also cancelled her upcoming Savannah, Virginia Beach, and Charlotte gigs through Saturday ... saying, "I am going home to be with my family. Thank you for your prayers and understanding."

Lauren was known to be a total daddy’s girl -- and previously spoke about how proud she was of her dad for beating his alcohol addiction ... adding his sobriety brought them closer together.

She also shared her dad was the inspo for her song "My Old Man," which she wrote in tribute to him for her wedding to Cam Arnold in Feb.

Lauren's last IG tribute to her dad was on Father's Day in June ... gushing his heart was the size of Texas alongside a bunch of pics of him in tears at her wedding.

J.J.'s death comes 6 years after Lauren lost her step-dad, Sam Ranker, to cancer.