In November, it was revealed that Ritchie would appear in the second series of Underbelly, as Judi Kane, the wife of slain 1970s standover man Les Kane. The series screened in 2009. This was her first TV drama role since leaving Home and Away. Throughout 2009, Ritchie continued her radio role on the Merrick & Rosso and Kate Ritchie Show.
In 2009 Ritchie became the face of Vaseline. It was announced on 7 November 2009 that Ritchie would host the 2009 ARIA Awards on 26 November, alongside actor and fellow Underbelly cast member Gyton Grantley.
On 10 November 2009, Ritchie announced she would be leaving Nova 96.9's breakfast team and returning to acting. In January 2010 it was announced that Ritchie had been cast with a lead role in Nine's new police drama Cops L.A.C. The series did not rate well and was cancelled after the season finale.