Gwen Stefani Catches NYC Subway to Plug 'The Voice'

Gwen Stefani took her B-A-N-A-N-A-S style straight to the subway -- injecting some much-needed glamour into New York City's gritty metro system.

Check out these pics -- Gwen gave the daily commuters a real treat Friday, hopping onto the subway like a regular rider with her MetroCard in hand in a bid to promote "The Voice" ... but let’s be real, she definitely stood out in that crowd.

As you can see in the video above ... Gwen was first seen strutting down the grimy subway stairs to the platform in knee-high heeled boots, her furry jacket casually slipping off her shoulders like she's runway-ready.

Her signature shades came off real quick ... but TBF, after years of hopping in and out of fancy rides, she probably forgot how dimly lit those underground subway tunnels are.

Gwen seemed to soak up the real commuter vibe, flashing a mega smile like she's loving every minute of the everyday hustle.