She would then go on to host several Australian TV shows, including Coxy's Big Break, Beyond the Boundary and Melbourne Woman.
In 2006, she earned her wings when she landed an 81-episode role as Pepper Steiger in the longstanding Australian hit soap opera, Neighbours. As of October 2012, the show has been running for 28 seasons with more than 6,000 episodes.
Whelan began posing for a number of Australian magazines, including Ralph in 2005 and FHM in 2007. She was featured on the cover of Pumped Up Down Under, an Australian magazine that voted her sports model of the year in both 2001 and 2007.
In 2007, she began supporting sustainable living and transportation in Harrow, London and helped to start up the city's "It's All Up to Us" campaign. That same year, she wrapped up starring in Hollywood and Wine with costar David Spade, whom she dated until 2008.
In 2009, Nicky started landing single episode guest appearances on big TV shows, including spots on Entourage and the new Melrose Place in 2009, as well as a role in the Rob Zombie remake Halloween II.
In 2010, Whelan began dating Guns N' Roses guitarist DJ Ashba after having been rumored as dating British boxer/male model, Gary Stretch. That year, she also appeared in the final season of NBC's hit hospital sitcom, Scrubs.
In 2011 she landed more one-off roles on American TV shows, including Comedy Central's Workaholics and NBC's Friends with Benefits, both as sexy guest starring characters.
Later in 2011, Whelan picked up a part on the comedy Hall Pass, costarred by Owen Wilson and Saturday Night Live's Jason Sudeikis.