Gwen Stefani, 50
The “ain’t no Hollaback girl” hasn’t aged a single day and credits her relationship with “The Voice” co-star Blake Shelton as a “healing” moment in her life. Gwen Stefani, now 50-years-old, was the lead vocalist for No Doubt before pursing a solo career in 2004. Along with her singing career, she released her own clothing line in 2004, a fragrance line in 2008 and an animated series in 2014.