Williams has not played competitively for nearly eight months after undergoing a knee operation but had hoped to make her comeback at the $600,000 event in Doha.
"I am really disappointed that I won't be playing Doha...I have been battling the 'flu for several days and am not quite 100 percent well yet," the American said in a statement.
"The good news is that the knee is feeling great and I feel I am back in championship form."
"I'm anxious to resume playing and looking forward to getting back on court and seeing my fans."
Williams's last competitive match was the Wimbledon final in July last year, when she beat sister Venus to capture her sixth singles grand slam title.
Images: Wimbledon 2001 final, Wimbledon 2002 final, Wimbledon 2003 final
The 22-year-old could make her return at the Nasdaq-100 Open in Miami in March.
