The 27-year-old won widespread compliments when she wore a white Sarah Burton-designed dress, as she served as her sister Kate's Maid of Honour at the royal wedding last week.
William Hill has now made Pippa 6/4 favourite to scoop the accolade, ahead of glamour model Lauren Pope and singer Adele. Pope is currently 6/1, while the 'Someone Like You' star has been given odds of 10/1.
"Pippa's bottom has been a trending topic on Twitter and has its own Facebook page," a spokesman for the bookmakers said. "It has caused quite a stir in the last week."
The Facebook group titled 'Pippa Middleton's Ass Appreciation' currently has almost 190,000 likes.
Award organiser Tony Edwards has reportedly described the support for Pippa as both "sudden" and "unexpected", while Metro claims that she received more than 1,000 votes in the 48 hours after the wedding.
Britain's Got Talent judge Amanda Holden and Dancing on Ice star Chloe Madeley are both currently 8/1 favourites for the win.
> Photo highlights: The royal wedding