Simon Oliveira said that the celebrity couple are "delighted to announce the birth of their daughter."
"Happy and healthy she arrived at 7.55 am this morning at Cedars Sinai hospital in Los Angeles and weighed 7lbs 10oz," Oliveira posted on Twitter, adding that the Beckhams' three sons "are excited to welcome their baby sister to the family."
The Beckhams, who married in 1999 and whose celebrity is entrenched on both sides of the Atlantic, already have three boys: Brooklyn, 11, Romeo, 8, and Cruz, 5.
The family have yet to announce a name for the little girl, who was born the morning after Beckham scored directly from a corner kick to give the Los Angeles Galaxy a 2-1 victory over the Chicago Fire, extending his team's Major League Soccer unbeaten streak to 12 matches.
The 36-year-old Beckham captained England's national team from 2000 to 2006. He played for Manchester United and Spain's Real Madrid before moving to L.A. to join the Galaxy in 2007.
Thirty seven year old Victoria Beckham found fame as a singer for 1990s girl band the Spice Girls and has since become a fixture of the fashion circuit.
Just days ago the LA Galaxy star posted a picture of his heavily pregnant wife on Facebook. Beneath the image which appeared to show his wife sunbathing Beckham wrote: "Took this pic of Victoria while she wasn't looking. She looks amazing, so close now to the baby being born!"