The Emmy-winning chat show host had already cancelled episodes of her LA talk show due to ill health during the week, including her final show ahead of her scheduled departure to Australia.
The delayed plans of the 55-year-old TV personality and her wife, Australian actress Portia de Rossi, have sent social diaries into a spin.
The couple were expected to attend a black tie cocktail party in Melbourne on Tuesday, among other social engagements.
DeGeneres was also reported to meet Prime Minister Julia Gillard during the day to discuss the highly emotive issue of gay marriage.
The chat show host said she was trying to get herself better before her big trip.
"Trying to get over a bug before I go to Australia. Nobody wants to be down under the weather," DeGeneres tweeted on Tuesday.
"Between my humidifier and Portia making me tea non-stop, there's so much steam coming from our house people think we picked the new Pope," she posted in a tweet a day earlier.
DeGeneres' Australian adventure has been 12 months in the making.
- AAP