Walking the zebra-adorned red carpet, new-mum Kate dazzled in floor-length sequin gown by Jenny Packham and wore her brunette hair in loose curls.
The Duchess of Cambridge accessorised the sequined maxi dress with a pair of matching Jimmy Choo heels and diamond jewellery.
William and Kate beamed as they walked into The Royal Society in London for the awards, hosted by journalist Kate Silverton, which recognise outstanding figures in African conservation.
"This is our first evening out without him [Prince George]," said Prince William. "Please excuse us if you see us nervously casting surreptitious glances at mobiles."
"Catherine and I very much hope to introduce George to east Africa – a place we know and love – in the fullness of time," added the Prince.
Dressed in a smart black suit William, who is the royal patron for Tusk Trust, appeared for the first time since announcing that he is leaving his job as an RAF search and rescue pilot.
During the evening the Duke of Cambridge presented two awards, a lifetime achievement honour called The Prince William Award for Conservation in Africa, was awarded to Clive Stockil and another accolade which recognises up-and-coming conservationist was won by Tom Lalampaa.
Kate has been seen in public since giving birth to Prince George on 22 July when she attended the The Ring O'Fire Marathon in Anglesey, although Thursday night's appearance was her first official engagement.
Africa holds a special place in the royal couple's heart after William proposed to Kate at a remote safari lodge in Kenya.
The Prince has long been involved with the work carried out by Tusk Trust and was made the charity's royal patron in 2005.
The ceremony was also filmed for a new documentary, airing on 15 September, which features new-dad William speaking about his passion for conservation coupled with his hopes for his family.
William and Kate previously joined forces to support Tusk Trust in April 2012 when they attended the London premiere of Big Cats and while on their tour to the USA and Canada.