Tennis superstar Serena Williams is used to hoisting trophies, but on Thursday she'll be carrying a wedding bouquet.

Music royalty Beyonce and Jay Z, along with actress Eva Longoria are among the A-listers reportedly convening in New Orleans for Williams' wedding to Reddit co-founder Alexis Ohanian.

People magazine and The Daily Mail, citing unnamed sources, have reported that about 250 guests will be invited to the ceremony at the Contemporary Arts Center in the Big Easy.

Wedding planning has been shrouded in secrecy and guests would not learn the details until Thursday morning, according to the Mail.

It said the event would cost more than $1 million and guests would be asked not to bring their cell phones because an exclusive photo deal has been signed with Vogue.

Williams, 36, a 23-time Grand Slam champion, and Ohanian, 34, welcomed their first child, daughter Alexis Olympia, on Sept 1.

They announced their engagement in December after meeting in 2015 in Rome.

Williams won this year's Australian Open while pregnant, and is expected to defend her title in Melbourne in 2018 - just four-and-a-half months after giving birth.