The cause of death wasn't immediately known. Police refused to provide further details.
Goo made her debut in 2008 as a member of the girl group Kara, which had big followings in South Korea, Japan and other Asian countries. She later worked as a solo artist and appeared on many TV shows.
Goo Hara rose to fame with South Korea's pop girl group Kara. File photo / supplied
In May, Goo was reportedly found unconscious at her home and was hospitalized. She was embroiled last year in public disputes with an ex-boyfriend who claimed to be assaulted by her. Goo accused the man of having threatened to circulate a sex video of her. The case made her the subject of tabloid fodder and malicious online messages.
In October, another K-pop star and actress, Sulli, was found dead at her home near Seoul. The 25-year-old was known for her feminist voice and outspokenness that was rare among female entertainers in deeply conservative South Korea. Before her death, she appeared in a TV show and spoke out against online backlash she received over her lifestyle.