Kate Middleton, the Duchess of Cambridge, attended a 100 Women in Hedge Funds Gala Dinner this evening to benefit Action on Addiction, a charity of which she is Patron.

Just one day after her son Prince George's christening, the Duchess was out and about to support the fight against addiction. She told Sky News of the day before that George "was such a good boy actually. We were very lucky, he's not always like that."

Kate arrived for the dinner wearing a off-the-shoulder silk tulle Jenny Packham gown, her hair in her signature blowout of long waves. The deep blue gown has a black velvet belt and short sleeves and a v-neck. Obviously, the new mom looked amazing! It must have been difficult for Kate to leave little Georgie at home, but he's in the capable hands of his father Prince William. We're not surprised to see Kate wearing Packham once again, as we know the Duchess is loyal to her favorite designers (and they're equally as good to her)!

Kate became Patron of Action on Addiction in January 2012 and wrote in a letter to 100WHF that she is delighted to see the two great organizations working together. Of her chosen charity, Kate said, "Those affected by addiction are in desperate need of the highest level of care and treatment; Action on Addiction delivers this brilliantly." All funds raised from the event this evening will go towards this cause.

Action on Addiction is a UK charity that works "across the addiction field in research, prevention, treatment, professional education, support for families and children and campaigns." You can learn more about Action on Addiction here.

Click through the gallery above to see more photos from tonight's event.