Camilla Luddington as Jo Wilson
Luddington was a star before she hit Grey's. She was Claudette in True Blood (2012), Lizzie in Californication (2012) and played Kate Middleton in the TV Movie William and Kate (2011).
Camilla Luddington in Behaving Badly
Luddington's second credited role (her first was in 2007) was in Behaving Badly (2009) as a flight attendant who helped a fellow cheat mid-flight.
Jerrika Hinton as Stephanie Edwards
Hinton has been in many series before she landed on Grey's in 2012 including Scandal (2012), Bones (2011), Terriers (2010), Gossip Girl (2009), Ghost Whisperer (2008) and Gilmore Girls (2006).
Jerrika Hinton in Hanes Commercial
HInton's first credited role was in a movie called Rain (2006). Finding her earlier roles is difficult, but she put some videos of commercials up on YouTube, including this Hanes "wedgie" classic she did with Sarah Chalke in 2008!