Fox-Pitt, 46, was placed in an induced coma after falling at the World Young Horse Championships in Lion D'Angers on 17 October. He was treated in France before returning to England last week.
"It is fantastic to be home," said the former world number one.
Fox-Pitt is GB's most successful rider with 20 major championship medals.
His horse Reinstated was unharmed in the incident in western France.
Fox-Pitt added: "It feels like a long time away from my family. I would like to thank all the doctors in France, and the rehab team in Poole General Hospital have been incredibly thorough.
"The team at home have been doing an amazing job keeping everything going, but luckily everything is quiet as the horses are all on their end-of-season break. I am looking forward to making a full recovery over the winter."
A statement from British Eventing added: "William has made good progress with his recovery and has now been discharged from hospital to continue his rehab at home. The family continue to ask for privacy as William recovers."

Northamptonshire Police tweeted live on Saturday night to show the problems in the county's town centres.
During the evening officers dealt with fights, drink-drivers and more than 100 999 calls after midnight.
The force said it hoped the tweets "highlighted the impact on the police".
Using the hashtag #alcoholharm, the force tweeted into the early hours about incidents in towns including Northampton, Daventry and Kettering.
Officers dealt with criminal damage, fights in the street, people assaulting nightclub and hotel staff and drink-drivers, including one man who was three times over the alcohol limit.
The force said since midnight its control room had received 187 calls, more than 100 of them via 999.
It added it dealt with 129 incidents in total, many of them drink-related.
After the night officers tweeted: "#alcoholharm is a social issue we all have a stake in solving.
"Hopefully tonight has highlighted the realities of dealing with drunkenness & the impact on the #police."
British eventer William Fox-Pitt has been discharged from hospital as he continues his recovery following a serious fall in competition last month.
[NEXT_CONCEPT]
A man dialling 999 to say he had been thrown out of a pub was one of a number of problem calls highlighted by a police force during a live Twitter session about excessive drinking.