"I'm up to s**t, I've got COVID," she told KIIS-FM Sydney radio on Thursday.
The diagnosis means the Queensland senator cannot campaign in person and will be in isolation on election day on Saturday.
Senator Hanson confirmed she was not vaccinated against the virus.
"I haven't been to hospital. I'm still kicking. I'm alive," she said.
Independent MP Andrew Wilkie also tested positive to the virus earlier this week, forcing him to cancel his final campaign appearances.
Meanwhile federal government data shows more than 60 aged care residents in Australia are dying with COVID-19 every week.
While many think the Omicron wave of the virus has passed, the health data gathered by a union reveals 596 aged care facilities have recorded at least one COVID death this year.
"How can we lose more than 350 senior Australians to COVID since the election campaign was launched and no one is talking about this," United Workers Union Aged Care Director Carolyn Smith said on Thursday.
"The Omicron crisis continues to play havoc with active outbreaks in more than 750 aged care facilities, distressing locked-up aged care residents, devastating families and causing unbearable workloads for aged care workers.
"For aged care workers working double shifts in full PPE there has been no let-up and the aged care crisis is in full swing."
Almost 60,000 new cases of COVID-19 and 53 deaths were reported nationwide on Wednesday.
Meanwhile, aged care workers in South Australia and Queensland will walk off the job on Friday in a continuation of industrial action for higher wages and more care time.
"Aged care workers are continuing to turn up to care for residents while these political leaders are only turning up for campaign photo opps," Ms Smith said.
LATEST 24-HOUR COVID-19 DATA:
NSW: 10,964 cases, 22 deaths, 1283 in hospital with 46 in ICU
Victoria: 13,201 cases, 14 deaths, 512 in hospital with 32 in ICU
Tasmania: 1076 cases, two deaths, 43 in hospital with two in ICU.
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