Try Not To Shed A Tear Watching This Emotional Goodbye To Legendary Olympian Michael Phelps

His reaction to the commercial is equally priceless.

The upcoming 2016 Olympics in Rio will sadly be Michael Phelps' last games.

The most-decorated Olympian of all-time, with a staggering 18 medals, will suit up one last time at the age of 31.

He told USA Today, "This is definitely for good ... No more after this."

Before he officially hangs up the swimsuit, Under Armour put together a touching commercial dedicated to the only U.S. swimmer to compete in five Olympic games.

The commercial showcases the work ethic of Phelps and the emotions involved with leaving the sport behind.

Despite the pain he has put in to achieve greatness, the commercial also shows his willingness to always jump back in the pool and swim the next lap.

While he isn't sure what he will do next, he is excited for his fiancée Nicole Johnson to give birth to their baby boy.

He told USA Today, "I was laying on (Johnson's) stomach the other night just listening and every now and then I'd feel something on my head ... It's really cool being able to go through this process for the first time. Something I'll remember forever."

Watch the Under Armour commercial below:

Before premiering the commercial online, Phelps and Nicole watched the commercial together for the first time and couldn't hold back the tears.

On that note, let's bring home some more medals!

You can listen to Lil Wayne's song called "Go Getta," which he dedicated to Phelps during the 2008 Olympics in Beijing.

Phelps said in a Today show interview in '08 that he listened to Weezy's track "I'm Me" during warm-ups, so Wayne went ahead and made a song just for him.

"Michael Phelps, this is for you baby!"