The seven-time All England Club champion will be the 25th seed, one spot behind Maria Sharapova.
In May, French Open officials declined to grant her a seed, touching off a debate about how the sport should treat its ranked players who return to the game following childbirth.
Slovakian world No. 32 Dominika Cibulkova was bumped from the seeding.
"But it's just not fair if there is a player [who misses out] and it's me now".
It reserves the right to change the women's seedings to "produce a balanced draw" and Williams, whose protected ranking does not guarantee a seeding, clearly is a special case. "I don't think it's the right thing to do", Cibulkova told BBC before the ruling.
She returned to tennis in early March at Indian Wells and having missed most of the clay-court season reached the last 16 at the French Open - where she was not seeded - before pulling out due to injury.
World Cup favourites Brazil beat Serbia to finish top of Group E
Serbia again set off alarm bells moments later, but some desperate Brazil defending was enough to keep them out. Others in the last 16 will be wary - the five-time winners mean business in Russian Federation .
Apple plans to launch new high-end audio devices
It will have noise cancellation and water resistance, but the latter will mainly protect the device against rain and perspiration. Ear headphones from Apple will compete with models in the medium price range from Bose and Sennheiser , said the source Agency.
United States sends coffins to North Korea for soldiers' remains
"We'll know pretty soon if they're going to operate in good faith or not", the official said , speaking on condition of anonymity.
The London slam has considered factors other than world ranking in the past, and the US Open announced Saturday it wouldn't penalize female players who were returning after pregnancy in seeding them. But, regardless of her current lowly ranking, if the 23-time major victor is over that fitness problem she will be a serious contender for yet another Wimbledon triumph.
"Why should I not be seeded if I have the right to be?" It's just because she won it many times and she's Serena Williams.
Due to this decision, Serena Williams will not face a seeded player until the third round. The slide resulted from a near year-long absence triggered by a freak injury, in which she stepped on broken glass and later developed blood clots in her lungs following her 2010 Wimbledon championship.
But the American has been slotted in between Maria Sharapova and Australia's Daria Gavrilova for Wimbledon after tournament officials decided the former victor deserved to be seeded.
Wimbledon will release the draw on Friday. Caroline Wozniacki, John McEnroe and USTA president Katrina Adams have spoken out in support of Williams.