If you haven't heard of her yet, Billie Eilish is the newest pop superstar rapidly taking over music and social media. With her alternative pop yet hip-hop-inspired sound, she's managed to become one of the most popular Gen-Xers in the industry today. 

And while her Instagram posts have probably come across your timeline, or you may have casually heard her songs on the radio, many people are still asking, "Who the heck is Billie Eilish?"

And there's nothing wrong with that, because we're here to give you the inside scoop into the teenage phenom that doesn't seem to be slowing down anytime soon. Happy learning. 

Her full name is Billie Eilish Pirate Baird O’Connell.

We must admit, the name Billie Pirate would have been pretty awesome, but in a 2017 interview with BBC, she explained exactly why that's not possible. "Pirate was going to be my middle name, but then my uncle had a problem with it because pirates are bad. Then Baird is my mother's name." 

And while a name inspired by the criminals of the sea might have been a pretty edgy flair to her name, Eilish will do. But if you're going to say it, make sure you pronounce it right: It's "eye-lish."

She's way younger than you think she is.

Just 17 years old. Yep, you read that right — she's not even legal yet. Born in 2001 (we feel old even saying that year), the young superstar is rising to stardom at a very early age. But she's seemingly far beyond her years, hanging out with much older celebs such as Khalid and Sza. 

She has an outrageous following: more than 18 million followers on Instagram.

She packs out just about any arena she's performing at with her alternative pop tunes paired with her hip-hop-inspired vibe. Initially gaining popularity through SoundCloud, her debut album, When We All Fall Asleep, Where Do We Go? was released late last month and has received wide-ranging acclaim since.

She's already performed at Coachella and she's not even old enough to drink yet.

At the 2019 installment of the Coachella festival in Palm Springs, she performed on the same stage as Kid Cudi and Solange — you know, totally casual for a teenager. If you haven't realized it yet, this girl is a really big deal. 

She's besties with singer Jessie Reyez.

The Toronto-born singer, who's 10 years Eilish's senior, has earned two iHeart Music awards nominations and has over 20 million streams on Spotify. Eilish surrounds herself with all the big winners, it seems.

She posted on her Instagram account to confirm that Tourette syndrome is a part of her life.

In late 2018, following a circulating video of her tics, Eilish revealed that she was diagnosed with Tourette as a child. Tourette, by the way, is a neurological disorder that causes a person to have involuntary physical or verbal tics. 

She's super inspired by the horror genre and shows such as The Walking Dead. 

In an interview with Harper's Bazar, Eilish said that one of her first songs, “Fingers Crossed,” was inspired by the zombie thriller. From the beat to even the words, she credits most of her inspiration to the things that creep most of us out. 

She comes from a family of entertainers.

Eilish grew up in the spotlight, with parents who are actress/musician/screenwriters Maggie Baird and Patrick O’Connell and her well-known brother Finneas, who also works in the industry as a musician, producer, and actor. 

She just announced her first world tour. 

With already 20 cities announced, she's hit the ground running. So if this has given you the itch to join Eilish's tens of millions of other fans, now is your chance to check her out live. Based on what we've seen and heard, you won't regret it.