Duchess of Cambridge Kate Middleton looked flawless in Alexander McQueen at Prince George's christening on Oct. 23 -- get the details on what she wore! Credit: John Stillwell/AFP/Getty

The Duchess does it again! Kate Middleton looked flawless -- as usual -- as she arrived at the Chapel Royal at St. James's Palace for Prince George's christening ceremony on Wednesday, Oct. 23.

Dressed for the celebratory occasion in a cream-colored dress with ruffle detailing by Sarah Burton for Alexander McQueen (also her wedding gown designer), the 31-year-old Duchess of Cambridge looked slim and elegant as she stood beside her husband, Prince William, and their baby son. A cream-colored fascinator and coordinating pumps completed the ladylike ensemble.

Prince George's christening outfit was even more noteworthy. The adorable little heir -- who turned 3 months old yesterday -- was resplendent in his white satin and Honiton lace christening gown, a replica of the one created for Victoria, Princess Royal, back in 1841. (Queen Elizabeth II commissioned the replica in 2008 in order to "preserve the original," which had survived more than a century of wear and tear and is now kept in the Museum of London.)

The royal baby and his proud parents were joined at the Chapel Royal by family members including Queen Elizabeth II, Prince Charles, Prince Harry, Carole and Michael Middleton, and James and Pippa Middleton. They are among a group of just 22 guests -- including Prince George's seven godparents -- who will take part in a 45-minute ceremony presided over by the Archbishop of Canterbury.

After the christening, the group will head over to Clarence House for a reception hosted by Prince Charles and his wife, Camilla, Duchess of Cornwall. "It will just be a small champagne reception," a source previously told Us of the gathering.