The past 12 months have been a whirlwind filled with high-profile celebrity weddings, career comebacks, movie releases, the birth of a little princess and more than a few squads!
In honor of the oh-so-memorable year, here is your A to Z guide to some of 2015's biggest highlights.
2/27
A is for Adele
The "Hello" singer made a triumphant comeback after a three year hiatus with her new album '25.'
Photo: GC Images
3/27
B is for Bob Brigade
A slew of celebrities changed up their looks this year with shorter 'dos, including Katy Perry, Jenna Dewan-Tatum, Emma Watson and Sophia Bush.
C is for Caitlyn Jenner
The 'I Am Cait' star made her grand debut on the cover of Vanity Fair over the summer saying, "Bruce always had to tell a lie... I am free."
Photo: FilmMagic
5/27
D is for Drake
It was the year of Drake with his hot single "Hotline Bling," along with his now-famous turtleneck sweater and meme-inspiring dancing in the music video.
6/27
E is for Eva Longoria
The 'Telenovela' star got engaged to boyfriend José "Pepe" Bastón in December while vacationing in Dubai.
Photo: Instagram/@evalongoria
7/27
F is for fabulous friends
Taylor Swift isn't the only celebrity with high-profile pals. Gigi Hadid & Kendall Jenner, Amy Schumer & Jennifer Lawrence and Selena Gomez & Jennifer Aniston gave us serious friendship goals in 2015.
G is for Gisele
After 20 years in the industry, the world’s highest-paid supermodel retired from the runway. She walked her last catwalk during Sao Paulo fashion week.
Photo: Getty Images
9/27
H is for Hiatus
One Direction announced they were going to take a break beginning in 2016. The news came the same year the band's fifth member, Zayn Malik, left the group in March to pursue solo projects.
Photo: WireImage
10/27
I is for iWatch
The latest Apple craze hit shelves in April, making us all want to communicate with each other via our wrists!
Photo: Getty Images
11/27
J is for #Jofia
Sofia Vergara and Joe Manganiello, appropriately dubbed "Jofia," tied the knot in November making them officially one of the hottest couples around.
Photo: Instagram/@sofiavergara
12/27
K is for Kanye (and the Kardashians)
While accepting the Michael Jackson Video Vanguard Award at the 2015 MTV Video Music Awards, Kanye West announced he was aiming for the United States' highest office, promising: "I have decided in 2020 to run for president."
It was a big year for Kanye. Aside from announcing his presidential candidacy, he and wife Kim Kardashian welcomed their second child, son Saint West in December.
Photo: Twitter/@KourtneyKardashian
13/27
L is for #LoveWins
On June 26, the Supreme Court delivered a historic decision, ruling 5 to 4 in favor of same-sex marriage across all 50 states. Following the landmark decision, President Obama tweeted, “Today is a big step in our march to equality. Gay and lesbian couples now have the right to marry, just like everyone else. #LoveWins."
Photo: Getty Images
14/27
M is for 'Mad Men'
It was the end of an era. The AMC drama series featuring Jon Hamm, January Jones, Elizabeth Moss, Christina Hendricks and Kiernan Shipka, came to a close after seven seasons.
Photo: Getty Images
15/27
N is for newbies on Instagram
2015 welcomed a slew of celebrities to the social media app, including David Beckham, Liam Hemsworth, Celine Dion, John Krasinski, Robert Downey Jr., Ryan Reynolds and Adele.
O is for over! (*tears*)
Some of Hollywood's most beloved couples headed for splitville this year including Gwen Stefani & Gavin Rossdale, Ben Affleck & Jennifer Garner, Blake Shelton & Miranda Lambert, Megan Fox & Brian Austin Green and Kate Hudson & Matt Bellamy — we are still recovering from them.
Photos: Getty Images/WireImage/FilmMagic
17/27
P is for Princess Charlotte
The latest addition to the Cambridge family was born May 2, 2015. Like her older brother Prince George, the precious princess has cherub cheeks and is sure to be a trendsetter like her mom, Kate Middleton.
Photo: HRH The Duchess of Cambridge via Getty Images
18/27
Q is for Queen Elizabeth II
The Queen became England's longest reigning monarch on September 9, 2015, beating her great-grandmother Queen Victoria's record.
Photos: Getty Images
19/27
R is for Rihanna
The singer showed up to the 2015 Met Gala, Through the Looking Glass, in a show-stopping coatdress designed by Chinese designer Guo Pei. Rihanna required the assistance of a red carpet army to help get her jaw-dropping attire up the steps of the museum.
Photo: Getty Images
20/27
S is for 'Star Wars!'
The force was strong with the return of the sci-fi franchise's seventh installment. With a new cast featuring Oscar Isaac, John Boyega, Lupita Nyong'o, Daisy Ridley and Adam Driver, the new film 'The Force Awakens' smashed domestic box office records its opening weekend.
Photo: Getty Images
21/27
T is for Taylor Swift
The "Bad Blood" singer embarked on her '1989' World Tour inviting numerous members of her infamous squad to join her onstage, including Hailee Steinfeld, Gigi Hadid, Lily Aldridge and Lena Dunham. The pop star also released her first concert film 'The 1989' World Tour (Live)' in December.
Photo: Getty Images
22/27
U is for Undercover Weddings
Jennifer Aniston and Justin Theroux surprised the world in August with their secret nuptials held at their Bel Air home in California. Also joining this year's roster of operative secret wedding planners are Mary-Kate Olsen & Olivier Sarkozy and Mila Kunis & Ashton Kutcher.
Sam Worthington and Lara Bingle also shared their news in 2015 that they tied the knot at the end of 2014.
Photo: FilmMagic
23/27
V is for Vegas
Celine Dion returned to the Las Vegas stage in August after taking a break from her residency to care for her husband René Angélil. Joining the "Power of Love" singer in Sin City in 2016 is Jennifer Lopez. It was announced that the "Booty" singer would headline her own show at Planet Hollywood beginning in January. Meanwhile, Britney Spears continues to kick it with her residency at the AXIS at Planet Hollywood.
Photos: WireImage, Getty Images, WireImage
24/27
W is for White House
Royals descended upon the 1600 Pennsylvania Ave. residence this year, including Prince Harry and King Felipe VI and Queen Letizia. While in D.C., the ginger-haired royal promoted the 2016 Invictus Games and met wounded military members alongside First Lady Michelle Obama and Dr. Jill Biden.
Photo: Getty Images
25/27
X is for X-Rated!
The highly anticipated feature film adaptation of E.L. James's best-selling book 'Fifty Shades of Grey,' starring Dakota Johnson and Jamie Dornan, hit theaters in February of 2015. Though it earned a place holding down our X category, the steamy flick was, of course, rated R.
Photo: WireImage
26/27
Y is for Yolanda Foster
The 'Real Housewife of Beverly Hills' continued to battle Lyme disease and revealed that she isn't the only member of her family who suffers – her son Anwar and daughter Bella Hadid have it as well.
Yolanda also gave the surprising announcement in December that she and husband David Foster were splitting after nine years together, four of which they were married.
Photo: WireImage
27/27
Z is for 'Zoolander'
Derek Zoolander (Ben Stiller) and Hansel (Owen Wilson) took to the runway during the Valentino Fashion Show during Paris Fashion Week. Their new film 'Zoolander 2' opens in theaters February 12, 2016.