《Fifteen》是由美国女歌手泰勒·斯威夫特演唱的一首乡村流行歌曲，歌曲的歌词和简谱由泰勒·斯威夫特编写，音乐制作由泰勒·斯威夫特和内森·查尔曼共同负责。这首歌收录自她的第二张录音室专辑《Fearless》，于2009年8月30日作为该专辑第五波主打单曲由大机器公司发行。

《Fifteen》讲述了泰勒在高中第一年的故事，她遇到了好友阿比吉尔，阿比吉尔亦是泰勒在高中认识的第一个朋友。泰勒称她很希望在她十五岁的时候能有一首歌，告诉她关于她这首歌里讲到的一些关于在高中的事情。

泰勒她以追溯的方式展开然后写完整首歌曲的歌词，整首歌曲都是围绕阿比吉尔在恋爱后受到辜负这一情节创作的。歌曲在创作之后泰勒询问阿比吉尔是否可以把这首歌曲放入专辑中，在得到同意后便开始与内森·查尔曼录制《Fifteen》。

You take a deep breath and you walk through the doors

It's the morning of your very first day

you say hi to your friends you ain't seen in a while

Try and stay out of everybodys way

it's your freshman year and you're gonna be here

for the next four years in this town

hoping one of those senior boys will wink at you and say

you know I haven't seen you around before

Cause when you're fifteen and somebody tells you they love you

you're gonna believe them

and when youre fifteen

feeling like there's nothing to figure out

but count to ten, take it in

this is life before you know who you're gonna be fifteen

You sit in class next to a redhead named Abigail

and soon enough you are best friends

laughing at the other girls who think they're so cool

we'll be out of here as soon as we can

and then you're on your very first date and he's got a car

and you're feeling like flying

and you're mama's waiting up and you think he's the one

and you're dancing round your room when the night ends

when the night ends

Cause when you're fifteen

and somebody tells you they love you

you're gonna believe them

when you're fifteen and your first kiss

makes your head spin round

but in your life you'll do things greater than dating the boy on the football team

but I didn't know it at fifteen

When all you wanted was to be wanted

wish you could go back and tell yourself what you know now

Back then I swore I was gonna marry him someday

but I realized some bigger dreams of mine

and Abigail gave everything she had to a boy

who changed his mind and we both cried

Cause when you're fifteen

and somebody tells you they love you

you're gonna believe them

and when you're fifteen,

don't forget to look before you fall

I've found that time can heal most anything

and you just might find who you're supposed to be

I didn't know who I was supposed to be at fifteen

la la la la la la la......

You're very first day

take a deep breath girl

take a deep breath as you walk through those door