Celebs Who Gave Fans the Surprise of a Lifetime at Their Wedding

Read on to find out which stars have crashed weddings…

1. Taylor Swift

Taylor Swift has become everyone's favorite wedding guest after crashing numerous events hosted by some lucky fans. When a couple decided to get married in the parking lot outside of one of her concerts, she immediately whisked them backstage for a celebration.

On another occasion, when the sister of a groom-to-be reached out to Taylor about her brother and his fiancee's love of her music, she knew she had to stop by. Taylor even sat down at the piano and played "Blank Space" -- a song special to the couple because the groom and his mom danced to the tune in the hospital before she passed away.

"Taylor knew exactly why she was coming there. She knew that the groom, who's also in the military, is a superfan, and so is his wife. When his sister told this to Taylor, she was able to convey this…These people have lost so much, and give so much still. It's fantastic," the wedding's DJ Michael Klebacher told Billboard.

2. Katy Perry

Katy Perry was on tour in St. Louis when she heard there was a wedding going down at the hotel where she was staying. The singer brought the entire touring crew with her as they barged into a ballroom at the Four Seasons hotel. Even though they weren't in wedding attire, the bride and groom didn't seem to mind. Katy only stayed for about 10 minutes but some of her dancers stuck around longer to dance the night away.

"It made the night. The wedding itself was just absolutely stunning, and the bride was beautiful. But that was the icing on the cake," a wedding guest told the Kansas Star.

3. Ed Sheeran

Ed Sheeran gave one deserving couple the performance of a lifetime at their wedding in Australia. The bride and groom had been going through a tough time and were actually gifted their wedding thanks to a radio station but had no idea about Ed's surprise performance. When it came time for their first dance, the radio hosts announced that the singer was going to be someone very special. The couple looked totally shocked when Ed made his way to the stage and he went on to perform "Thinking Out Loud."

4. Justin Bieber & Selena Gomez

Back in 2011 when Justin Bieber and Selena Gomez were dating, they crashed a fan's wedding in Malibu. The couple were on an evening walk when they heard one of Justin's songs playing somewhere nearby. They followed the sound and discovered a beachside wedding and decided to stop by. Even though they were only there for a few minutes, it was enough time for Justin to jump on stage and congratulate the happy couple.

"We just crashed it. We heard a party so we decided to just come. So let's party," Justin said on stage.

5. Tom Hanks

Tom Hanks was taking a stroll on the beach in Santa Monica when he suddenly found himself in the middle of a wedding ceremony! The actor couldn't help but stop by to say hello and even told the two brides that it was one of the most beautiful weddings he'd ever seen.

"Tom Hanks walked through the whole crowd and said, 'Hey I just had to stop and see these beautiful brides!' He stuck around for about five minutes and gave us a very good, positive talk," one of the brides told KTLA.

The "Forrest Gump" actor also took the time to officiate another couple's wedding in Pittsburg after a series of pop ups around the area. In an interview with CBS Pittsburgh, Krisna Poznik and her now husband Tyson detailed how the couple were able to get the Oscar Award winner to be a part of their big day.

"We knew that he was an ordained minister, and they were filming right in the neighborhood, so I thought, 'Hey, what does it hurt to ask?' I wrote a letter, explained who we are and we're close by, and it's always been our dream to get married at our house," Krisna said. "We asked and he said yes!"

6. Kristen Stewart

Two Canadian brides got a special surprise from Kristen Stewart at their wedding — except they had no idea who she was! The couple were hosting their wedding reception at Pizzeria Gusto, a restaurant where Kristen had recently hosted her own event. The owner knew Kristen was still in town and invited her to stop by, with the brides' permission, of course! Kristen stayed throughout the evening and enjoyed dinner, drinks and dancing with the rest of the guests.

"The owner came up to me, and he said, 'Hey, is it OK if Kristen Stewart and her girlfriend Stella [Maxwell] come and have a few drinks with you guys?' and I was like, 'Yeah, totally! Yeah, no problem. Um, who is that?'" one of the brides told the Canadian Broadcasting Co.

7. Meryl Streep

Meryl Streep accidentally crashed a couple's wedding while she was filming a movie! The actress was working on "Iron Lady" and was filming at Manchester Town Hall in the UK -- right where the couple happened to be getting married. Meryl, along with the rest of the cast and crew, applauded the bride as she made her grand entrance and presented her with champagne, flowers, a glass vase and a copy of the film's call sheet for the day. Meryl later sent the duo signed pictures with her congratulations.

"It was all very surreal - Meryl Streep was standing there dressed as Margaret Thatcher. It almost feels like it didn't happen. I thought it was amazing, the last thing you expect is an A-List celebrity at your wedding," the bride Freya told Daily Mail.

8. Lady Gaga

Lady Gaga was in New York City promoting her album "Joanne" when she came across a couple taking photos for their wedding in Central Park. The musician had to stop to compliment the bride, telling her that she looked beautiful and briefly speaking in Japanese with the couple.

"See, all you need is love right? Have a beautiful marriage," Gaga told the couple before continuing on her way.

9. Justin Timberlake

Justin Timberlake scored a special invite to a fan's wedding moments before it happened, courtesy of the father of the bride. He spotted the star at a restaurant before the affair was supposed to begin and asked Justin if he would stop by later. Justin obliged and made an appearance as the couple were snapping photos before the reception.

"So we were taking the first look photo and all of a sudden Justin Timberlake appears out of nowhere, shakes my husband's hand and congratulates us and takes a photo. We thought it was awesome of him to do that, but had no idea it would go viral," the bride told Entertainment Tonight.

10. John Travolta

John Travolta is no stranger to wedding crashing! Back in 1977 he says he crashed an event with Robin Williams but more recently he stopped by a ceremony for a photo op. According to a friend of the couple, John first met them at a bar the night before the wedding. They ended up inviting the actor to the event and he actually showed up! The friend went on to say that John was "nice and down to earth about the whole ordeal."

11. Maroon 5

Maroon 5 once crashed a bunch of weddings in one weekend -- and documented it all for a music video! The band set out to stop by as many weddings as possible and totally surprise the brides with a performance of their song "Sugar." Lead singer Adam Levine says it was "really stressful to arrange all of it, but it was super fun." And according to the band's rep, only the grooms were in on the stunt and the reactions from everyone else was totally genuine.

"Only the grooms knew in each case. However they disclosed it to their bride and the wedding party, we're not sure, but they all wanted it to be as equally a surprise as we did. They had stages set up for their actual wedding band already. All we did was some simple continuity changes to match each one as best we could," the rep told ET.

12. Bradley Cooper

Bradley Cooper was visiting his alma mater Georgetown University when he bumped into a couple who were taking wedding photos around the campus. Not only did he stop to talk to the happy couple but he also popped into their reception later in the evening. The groom's father, a political commentator and journalist for MSNBC, gave some more details during a television appearance.

"That was in Georgetown right before the wedding with Bradley Cooper, who caught the bouquet," Mike Barnicle said on "Morning Joe."

13. Dwayne Johnson & Danny DeVito

Dwayne Johnson and Danny DeVito were in Mexico promoting their movie "Jumanji: The Next Level” when they learned there was a wedding happening at their hotel. The duo headed upstairs and burst into the room singing "Unforgettable" by Nat King Cole.

"What started off as a quiet sunset Teremana tequila toast with mi amigo, Danny DeVito - turned into Wedding Crashers 2.0.  So much love and mana in the room for the lovely bride & groom. Congrats Will & Kristine Abbot!" Dwayne wrote on Twitter.