Happy Election Day!

The months of campaigning are finally over, and now it's time to cast a vote for the next President of the United States.

In the days leading up to Tuesday, Nov. 6, President Barack Obama and his opponent, Republican nominee Mitt Romney, pulled out all the stops to get their messages out to voters -- and then to get those voters out to the polls.

And they weren't the only ones. On Monday, the eve of Election Day 2012, superstar Beyonce Knowles took to her website with photos of herself filling out her ballot and a handwritten letter to Obama, thanking him for inspiring Americans to "give more of [themselves]."

PHOTOS: Celebs vote in the 2012 election

The "Love on Top" singer's message to the President, and to her fellow voters, is just one of many from politically passionate celebs this week. Jennifer Lopez, Lady Gaga, Mariah Carey, Ryan Seacrest, Lenny Kravitz, and countless others also stormed the Internet to get out the vote. Some shared stories and photos of their own experiences at the polls, while others simply encouraged fans to make their voices heard.

Us Weekly rounded up some of the stars' Election Day tweets and posts:

Alicia Keys @aliciakeys: Today's the day!!!! We are a great people of great power!!! ;-) Who voted already today???

America Ferrera @AmericaFerrera: Mission accomplished! I voted! My polling place needed more workers though, so that's what I'll be doing next election...

Demi Lovato @ddlovato: My first time voting!! Make sure to vote! Every vote counts.

Dwayne "the Rock" Johnson @TheRock: Before I vote - final question...who wakes up first and starts kickin' ass before sunrise? @MittRomney or @BarackObama

PHOTOS: Stars' political affiliations

Ellen DeGeneres @TheEllenShow: If you want to see change... vote. If you want equal rights... vote. If you want good deals on holiday sweaters, go to jcp. Then vote.

Jennifer Lopez @JLo: If you are an American, today is the day to make your voice heard! Find your polling place and vote today!

Khloe Kardashian @KhloeKardashian: Agree, disagree, but make YOUR choice and VOTE. The beauty is we all have a voice and the freedom to choose. #America

Lady Gaga @ladygaga: Daddy said there's lines AROUND THE BLOCK to vote in NY, way more than 4 years ago! This is so great. Anyone else's state see a lot of voters?

Larry King @kingsthings: I voted this morning in #BeverlyHills - I was the first one to vote in my district. #electionday

Lena Dunham @lenadunham: Ladies, put on your voting best. May I plz see pics of your voting "looks"?

Lenny Kravitz @LennyKravitz: Let's vote, y'all. I'm up and been in line. And yes, good morning.

Ludacris @Ludacris: Vote for Pres Obama & if u live in L.A. make history & vote for Jackie Lacey for District Attorney, she will be the 1st African American!

Mariah Carey @MariahCarey: Let your vote be heard!! Four more years!

Nicki Minaj @NICKIMINAJ: Beyond proud of your passion to let your voice be heard. Happy Election Day

Octavia Spencer @octaviaspencer: Listen, no matter where you stand on political ideology, please let your voice be heard. #Vote2012 It's the only power you have!!!!!!!

PHOTOS: Obama's A-list pals

Rashida Jones @iamrashidajones: Ladies, this is our election. DON'T TAKE YOUR RIGHTS FOR GRANTED. Old dudes want to control your bodies w/laws. Don't let 'em. VOTE.

Rosario Dawson @rosariodawson: This is your last shot to have your voice heard for two more years. Don't miss it, go out and #VOTE! #NOV6 #ivotebecause

Ryan Seacrest @RyanSeacrest: Ballot filled out, just gotta drop it off after work. #ivoted #almost

Sean "Diddy" Combs @iamdiddy: I voted today. Retweet if you made it to the voting booth!

Solange Knowles @solangeknowles: I can't say it enough. EVERYONE MUST get out today & VOTE. Our destiny...our grandchildren's destiny, is in the hands of our own.

Soleil Moon Frye @moonfrye: Just voted & the woman in front of me proudly handed over her license. She was 100 years old. #proudtovote Go vote!

Stephen Colbert @StephenAtHome: Make sure you get out there and VOTE today! Then enjoy your orange juice and cookie... wait! Did I just give blood by mistake?

This article originally appeared on Usmagazine.com: Election Day 2012: Celebs Hit the Polls, Encourage Fans to Get Out the Vote