Representatives for the creator of "Star Wars" announced the birth Monday.
Lucas, 69, and Hobson, who is president of Ariel Investments, were married in June.
In July, their wedding reception -- attended by many Hollywood stars and high-profile Chicagoans -- was held at Promontory Point.
The baby girl is named Everest Hobson Lucas.
She is the couple's first child and was born Friday via surrogate.
Hobson is Lucas' second wife and chairman of the board for DreamWorks Animation. Lucas also has a 32-year-old daughter, a 25-year-old daughter and a 20-year-old son. He was previously married to film editor Marcia Lou Griffin.
The Associated Press contributed to this report.