Over 10,000 athletes from 206 countries will compete for 4,924 medals across 42 sports over the next fortnight.
From the track to the taekwondo arena -- new champions will be crowned and new legends will be made.
CNN has taken a look into the Olympic crystal ball and offered some bold predictions where the stories might be made -- and where you might want to take a look.
It's the question they're all asking -- can Usain Bolt do the "Triple-Triple" in Rio?
For the third Olympic Games in a row, the world's fastest man is hoping to win the 100 meters, 200m and 4x100m relay and become the first athlete to ever achieve the feat.
Bolt, now 29, has had his share of injuries this season and was forced to pull out of the Jamaican trials with a minor hamstring tear.
He will face stern competition in the 100m from Justin Gatlin -- the man who Bolt defeated by one-hundredth of a second at the World Championships in Beijing last year.
Gatlin, who was banned for doping earlier in his career, posted the fastest time of the year during the U.S. trials after running 9.80.
Bolt, though remains confident as ever.
"This is where history is going to be made," he said before running in London earlier this month where he cruised to victory in the 200m.
"I'm looking forward to going down there and doing my best and putting on a show for the whole world to see."
History may be made -- but Bolt might be beaten to it by another Jamaican.
That would be Shelly-Ann Fraser-Pryce who is aiming to become the first athlete to win three successive 100m titles at the Games.
Victorious in Beijing in 2008 and in London four years ago, she will have to produce something special to win a third.
Fellow Jamaican Elaine Thompson ran the fastest time this year in July, while Dutch star Dafne Schippers is the favorite.
Making a splash
The U.S. will be hoping to dominate the pool and with Katie Ledecky in such sensational form it's difficult to see others getting a look in.
The 19-year-old Ledecky, who won Olympic gold in the 800m in London four years ago, has set 11 world records and won every major international race she has competed in.
She holds world records in the 400m, 800m, and 1,500m freestyle and is going for gold in the 200m, 400m and 800m freestyles in Rio.
Ledecky will face competition from teammate Missy Franklin who won four golds and a bronze in London at the age of 17.
Franklin is competing in the 200m backstroke and 200m freestyle and will be right in the mix.
While Ledecky and Franklin are heading to their second Games, Michael Phelps will compete in his fifth.
The 22-time medalist, who has won 18 golds, had quit the sport after London 2012 before returning two years later.
He'll be up against Ryan Lochte who has won five Olympic golds and 11 medals in all.
The pair will go head-to-head in the 200m individual medley.
And make sure you keep an eye out for Adam Peaty who is aiming to become the first British man to win Olympic gold in the pool in 28 years.
The 21-year-old is hot favorite and could be one of the stories of the Games.
Two years ago it all ended in tears for Neymar and Brazil's footballers as it crashed out of its home World Cup at the semifinal stage.
Thrashed 7-1 by eventual champion Germany, a nation went into meltdown over its biggest football failure since 1950.
This time around Neymar is back to help lead his country to Olympic gold -- a feat it has yet to achieve.
The five-time World Cup winner was beaten in the final by Mexico at London 2012 but is fancied to go one better this time around.
Barcelona star Neymar is joined by Bayern Munich's Douglas Costa and Paris Saint-Germain defender Marquinhos.
His fans call him "Superman" and the London 2012 all-around champion will be aiming to fly to a second consecutive gold medal.
After claiming silver in Beijing four years earlier, Kohei Uchimura held his nerve to underline his credentials as one of the best gymnasts on the planet.
He's won four silvers in all, while he has 10 world championship golds to his name.
By the time the Olympics heads to his home country of Japan he will be 31 -- but don't bet against him going into those Games as reigning champion.
While Uchimura has seen it all before, U.S. sensation Simone Biles is preparing to make her debut at the Games -- but with the extra pressure of being huge favorite for gold.
The 19-year-old became the first woman to win three consecutive all-around world titles when she won gold in Glasgow last year.
She has won 14 medals at the world championships in all -- 10 of those gold -- and will also spearhead the team event.
Biles will challenge defending champion Gabby Douglas who won the all-around event four years ago and was part of the U.S. team which won gold in London.
While Biles is making her debut at 19, Uzbekistan's Oksana Chusovitina is set to become the first female gymnast to compete at seven Olympic Games
The 40-year-old, who won gold at Barcelona in 1992 with the Unified Team, won silver in the vault while representing Germany at Beijing.
But there will be no room for 75-year-old equestrian star Hiroshi Hoketsu
after he failed to make the Japan team.
Hoketsu made his Olympic debut in Tokyo in 1964 and was the oldest athlete to compete in the 2012 London Games at the Japanese record of 71.
He failed to qualify this time around after his horse became ill.
Keep any eye out
While the Olympics plays host to all the usual sports, there are a number of new events or returning events in Rio this year.
Lydia Ko is hoping to become the first woman to win a gold medal in golf with the sport returning to the Games for the first time since 1904 -- an event in which only men competed.
Rugby Sevens makes its bow at the Olympics with New Zealand and Fiji expected to do battle for the title in the men's competition, while Australia is favorite in the women's.
Elsewhere, British trio Jessica Ennis-Hill, Greg Rutherford and Mo Farah are all hoping for a repeat of 2012's "Super Saturday" where they all won gold.
Ethiopia's Genzeze Dibaba. the 2015 Laureus female athlete of the year, broke three world records in two weeks, setting new marks in the 1500m indoor, 3000m and two mile indoor events last year.
The 25-year-old will be going for gold in the 1500m.
In fencing, Italy's Rossella Fiamingo will be looking to add the Olympic épée title to her two world championship crowns.
In archery, look out for Kim Woojin of South Korea, who has already won two world championship titles.
The 24-year-old missed the cut in 2012 but will be one of the favorites this time around.
Brazil's beach volleyball duo Talita Antunes and Larissa Franca are big favorites to win gold in their home Games.
The duo are seeded No.1 in the draw and were winners of the 2015 FIVB Beach Volleyball World Tour.
In boxing, check out Britain's Nicola Adams -- the reigning Olympic, world, Commonwealth and European Games champion.
The 33-year-old flyweight is aiming to become the first British boxer since Harry Mallin in 1924 to successfully defend an Olympic gold medal.