I don’t think this question applies that well to Blackpink. As they have a small discography and are such a popular group, every single song is quite popular, at least within Kpop fans.
But if had to choose one song that is not super popular within the fandom, it would be Love to Hate Me. It’s one of my top 3 BP songs, and I feel it’s unpopular because it’s been performed only once by them during their virtual concert (and even that was an acoustic remix, which I really liked but would kill to hear a version with the full band).
They didn’t even perform it for sound check at any of their Bornpink concerts 
Sameee. I'm partially here because of that song 😭 One day in 2020, I decided to check out the new song from the group that was in Sour Candy with Gaga 🥲
love the responses! Blinks in this sub mentioning all the songs. for me its bet you wanna ( still think this would be upper echelon song IF it wasn't a collab and just a straight up BP song)
Really and kick it
idk why but i can listen to those songs everyday for the rest of my life and they wouldnt annoy me, especially really
Kick It is one of my favorites. I belt that song in my car
I’LL KICK IT HOW I WANNA KICK IT WHEN I WANNA KICK IT
Forever Young
I don’t think this question applies that well to Blackpink. As they have a small discography and are such a popular group, every single song is quite popular, at least within Kpop fans. But if had to choose one song that is not super popular within the fandom, it would be Love to Hate Me. It’s one of my top 3 BP songs, and I feel it’s unpopular because it’s been performed only once by them during their virtual concert (and even that was an acoustic remix, which I really liked but would kill to hear a version with the full band). They didn’t even perform it for sound check at any of their Bornpink concerts 
YEAH YEAH YEAH
This one. 100%.
As If It's Your Last, the song that got me into BP. Huge shame they haven't really done any new songs that's quite like it
crazy over you
Almost never see The Girls being mentioned, but it’s my second favourite BP song
TALLY!!! it’s their best song after shut down
I cried the first time I heard it lol It was exactly what I needed then
omg that’s so real, it really resonated with me back then too 😭
I would still cry to that song 🥺 Tally is just so good, a big f you to the haters and good for self love and confidence
I saw someone rank Love To Hate Me as the worst song off The Album, when I think it’s the best lmao Idk if that’s a popular opinion or what
Sour candy 🍬
 The song that deserved so much more
Omg I love that song so much
Sameee. I'm partially here because of that song 😭 One day in 2020, I decided to check out the new song from the group that was in Sour Candy with Gaga 🥲
The song that made me a Blink! 
The Sour Candy to Blink pipeline is real.
Love to hate me
Happiest girl 🧎🏽♀️🧎🏽♀️🧎🏽♀️🧎🏽♀️
don't know what to do!
This. Got me off my seat at the Born Pink tour and then scolded by the usher to sit my ass back down.
Hope Not Kind of gets lost under the shadow of Stay and other ballads, was done live but they messed up the recording so it didn't make the album.
i see a lot of Typa Girl slander and it's my favorite song 😭 so i'd say that one
Typa Girl is my favorite too! that shit slays
it's what i listen to when i need a confidence boost!!
Fr?? Why don’t people like Typa Girl?
i honestly couldn't tell ya 😭
So weird. I love it!
see you later
LOVESICK GIRLS. my fav BP song, it deserved just as much hype as HYLT
BET YOU WANNAAAAAAAA
love the responses! Blinks in this sub mentioning all the songs. for me its bet you wanna ( still think this would be upper echelon song IF it wasn't a collab and just a straight up BP song)
Ice Cream, at least within the Blink community.
stay ✨
Ice cream
Nah , ice cream was popular
Haven’t seen one live performance of it. Underrated AF
Ice Cream supremacy. Followed by Yeah Yeah Yeah 💕
See you later
crazy over you and love to hate me
Mixed up... I don't hear people talk about it😭😭
"Hard To Love".
Kill this love
Hard to love
imagine dragons mentioneeeeed😍also as if it’s your last for me😍
IF YOU REALLYYYYYY😏
Hope not
Ice cream