The 26-year-old visited the makeshift memorial outside the hotel where fans have showed their respects by laying flowers and tributes, a website reports.
According to eyewitness Rik Feydick, the Glee actress didn’t leave the SUV she was travelling in but peered through the windows, hiding behind giant black sunglasses.
The vehicle quickly sped off after Lea and her two bodyguards realised they had been spotted.
The visit follows a private cremation service held for Cory earlier this week, attended by Lea and Cory’s mother.
She had earlier visited the hospital to view Cory’s body and has reportedly played an important part in making arrangements following his tragic death.
Following an autopsy and toxicology report that revealed Cory died from a lethal combination of heroin and alcohol, former Disney star Demi Lovato has spoken out in defence of her friend’s untimely death. Lovato told a magazine that he was a ‘tragic victim of addiction’ and didn’t ‘choose to die’.
Cory struggled with addiction problems as a teenager, attending rehab aged 19 and most recently, this year in April. Girlfriend Lea released a statement at the time saying how proud she was of him and how she fully supported him in his attempt overcome the disease.
Monteith was found dead in his hotel room on Saturday. He was 31.