The former Neighbours actress, who got together with long-term friend and Young Talent Time host Mills last year, reportedly broke up with him after experiencing a recent health scare.
McIntosh told Woman's Day magazine that she and Mills had a "bit of fun for a few months", adding that he is "someone [she's] known for a very long time".
She also said that she has "great memories" of their romance, even joking: "I'd even like to think I played a very small role in helping Rob get over [ex-girlfriend] Paris Hilton!"
McIntosh explained that her fling with Mills fizzled out after she was hospitalised with viral meningitis.
She said of the health scare: "I ended up spending the night on the bathroom floor, with violent nausea, pain in my neck, an out-of-control fever and an excruciating headache that felt like a metal ball was rolling around inside my skull.
"Looking back, I'm not sure why I waited until morning to call my parents for help, but I think I was in denial as I'd barely ever been sick before in my life."
McIntosh made a full recovery after spending a week in hospital.
> 'Young Talent Time's Rob Mills: 'I still have a lot to learn'