Luke Robertson, 30, from Stonehaven in Aberdeenshire, hopes to become the youngest Brit to achieve the feat, in aid of the charity Marie Curie.
Mr Robertson, who now lives in Edinburgh, is spending 40 days alone dragging 130kg of equipment across 730 miles of ice, burning more than 10,000 calories per day while braving temperatures of -50C and 100mph winds.
He has already travelled almost 300 miles since setting off from Hercules Inlet on the edge of Antarctica on December 5.
The adventurer was inspired to embark on the challenge after overcoming a series of health problems, including surgery to remove a suspected brain tumour a year ago, which turned out to be a large and rare cyst.
He also had a pacemaker fitted at the age of 23 after suffering a complete heart block.
Mr Robertson decided to donate the money raised from the Due South 2015 expedition to Marie Curie after witnessing first-hand the “amazing” work of the charity’s nurses.
He said: “I have been overwhelmed by the support and generosities I have received so far in my fundraising efforts and know the infinite encouragement will enable me to push myself further and keep me smiling when I spend Christmas Day alone.
“I’ve seen first-hand the strength of the human character and hope that through undertaking this extreme endurance expedition, I can inspire others and demonstrate the ability to overcome even the most testing situations.”
Dr Jane Collins, chief executive of Marie Curie, said: “Luke’s story is incredibly inspiring and I would like to thank him on behalf of everyone at Marie Curie for taking on this amazing personal challenge.
“He is a true inspiration to others and we know that his Antarctic adventure will make a real difference to people living with a terminal illness and their families.”
The expedition has received high-profile support from explorer Sir Ranulph Fiennes and cyclist Mark Beaumont.
Mr Robertson’s progress can be tracked and donations made at www.duesouth2015.com.