The All England Club fined the American tennis pro for damaging a court during practice before the start of the Grand Slam tournament, although further details surrounding the incident were not immediately available.
According to DailyMail reporter Mike Dickson, the fine came after Williams threw her racket, causing some sort of damage to the famous English grass courts.
Williams' fine is one the largest of the tournament this year by far.
Italian Fabio Fognini was fined $3,000 during his third-round loss after saying he wished a bomb would hit Wimbledon.
Nick Kyrgios was handed two fines, one for $3,000 from the first round and another for $5,000 from the second round — both for unsportsmanlike conduct.
Australian tennis player Bernard Tomic was hit with the largest fine -- his full prize money of $56,500 in the first week of Wimbledon for not meeting "the required professional standards" in his first-round loss. His fine, unlike the others, was for a lack of effort, a penalty he can appeal.
Williams eased into the Wimbledon quarterfinals for the 14th time Monday by beating Carla Suarez Navarro 6-2, 6-2. She is looking for her eighth Wimbledon title after losing last year's final to Angelique Kerber.
The Associated Press contributed to this report.