Cody Simpson -- I Got Your Crash Pad Right Here, Gigi Hadid!

Cody Simpson ain't your average struggling 18-year-old ... the singer just scored his own townhome in the middle of West Hollywood -- and no one's happier than his smoking hot GF Gigi Hadid.

Our real estate sources tell us the Aussie pop star laid down $1.18 million for a 2 bedroom, 3 bath unit. It's got just over 1,600 sq. ft. ... a ton of space for a teenager striking out on his own.

Cody's also getting some sick city views from his FOUR outdoor patios and rooftop deck -- and best of all ... he can share that with modeling's 'it' girl, Gigi.

The pad is a major bonus for Hadid ... who now gets a place to crash near all the action in Hollywood -- instead of trekking out to her parent's Malibu mansion.