Serena Williams has been fairly private about her relationship with Alexis Ohanian, but after trading her fans on Instagram she finally revealed her massive engagement ring on Reddit, the site her fiancé cofounded. The rock seems to take up a lot of space on her ring finger.

Ciara's quarterback boyfriend, Russell Wilson, popped the question while the two were vacationing in the Seychelles with a glitzy diamond. Russell tweeted a sweet video of the two post-engagement, captioning it "Every Morning, Every Night... I Thank God for you @ciara."

While Kylie Minogue's 28-year-old actor boyfriend, Joshua Sasse, reportedly popped the question back in January, the Australian pop diva officially debuted her stunning engagement ring on the red carpet at the 2016 NME Awards in London.

Mariah Carey's billionaire boyfriend, James Packer, proposed at an NYC restaurant in front of Carey's closest friends, getting down on one knee and presenting her with the emerald-cut stunner.

The actress donned her brilliant round engagement ring while attending the Golden Globes with fiancé Jason Stratham

Longoria's boyfriend, Jose Antonio Baston, proposed in Dubai with a ruby ring surrounded by diamonds. Longoria shared a sweet snap of the couple on Instagram, writing, "Ummmm so this happened....#Engaged #Dubai #Happiness"

The designer's engagement ring from fiance Olivier Sarkozy is a 4-carat vintage Cartier sparkler purchased at a Sotheby's auction.

Joe Manganiello and Sofia Vergara became engaged in December 2014, but last night's Screen Actors Guild Awards gave us our first look at Vergara's stunning oval-cut sparkler.

Diaz married Benji Madden on January 5, 2015, but was spotted with a sparkler on her ring finger in October 2014.

George Clooney presented his wife-to-be with a seven-carat emerald-cut diamond set in platinum.

Johnny Depp confirmed his engagement to Heard when he wore her ring during the press tour for his film Transendence. He designed this one for his fiancee, but it was too big for her finger. To hold her over until it gets resized, Depp bought her another ring, this time from an antique store.

Kunis and her That '70s Show co-star became engaged just last month, and Kunis debuted her diamond ring (and baby bump) at Sunday night's MTV Movie Awards.

Williams' fiancee, Ricky Van Reen, selected the ring when the couple got engaged in February.

Kanye proposed to Kim with a 15-carat Lorraine Schwartz diamond ring at San Francisco's AT&T Park in October 2013.

Scarlet Johanssen's engagement ring from fiancée Romain Dauriac is a vintage Art Deco piece featuring three round cut diamonds and rows of pave diamonds on a tiered setting

Wilde's engagement to Jason Sudeikis called for diamond surrounded by a ring of emeralds—a gorgeous way to incorporate color—set on a thin gold band.

Ryan Reynolds created a custom ring with Lorraine Schwartz for bride Blake—the oval diamond is light pink and sits on a rose gold band of pavé diamonds.

Justin Theroux gave Aniston an emerald-cut diamond ring in August 2012, and the couple is set to tie the knot some time this year.

Brad Pitt designed Angie's ring with jeweler Robert Procop, ensuring the diamond was of "the finest quality and cut it to an exact custom size and shape to suit Angelina's hand." A representative told CNN after the engagement's announcement that "the side diamonds are specially cut to encircle her finger."

Olivier Martinez proposed to Berry with a Robert Mazlo 4-carat emerald in March 2012.

Barrymore's husband, Will Kopelman, selected the radiant-cut jewel from Graff Diamonds.

After Irina Shayk nailed the Victoria Secret runway and announced her baby news with Bradley Cooper we could only hope that wedding bells were on the way. Finally making all our dreams come true, the model stepped out for a spa day in LA donning a stunning emerald engagement ring.

Justin Timberlake selected the ring for his wife to be when the couple became engaged in early 2012

Matthew McConaughey proposed to Alves on Christmas morning 2011 with a rose-cut diamond.

Hathaway's fiancee, Adam Shulman, worked with Kwiat jewelers, who use only conflict-free diamonds, on the Oscar winner's emerald-cut jewel, which is set on a thin band studded with diamonds.

Portman's fiancee, Benjamin Millepied, and jeweler Jamie Wolf designed the Oscar winner's ring with her environmentally-conscious ideals in mind: the diamond is an antique and the surrounding pavé diamonds are conflict free, while the band is made of recycled platinum.

Kate's engagement ring from husband Jamie Hince is inspired by one owned by Zelda Fitzgerald.

Though she has yet to confirm her engagement to partner Guillaume Canet, Cotillard has sported an understated diamond on her ring finger since late 2010.

Richie worked with jeweler Neil Lane on the design of her four-carat ring for her engagement to Joel Madden.

Prince William gave Kate Middleton the famouse sapphire-and-diamond ring that belonged to his mother, Princess Diana.

Cruz's vintage ring from husband Javier Bardem features a three-carat sapphire surrounded by diamonds.

Blunt's three carat diamond and platinum ring from husband John Krasinki was custom made by Neil Lane

Blunt's three-carat diamond-and-platinum ring from husband John Krasinski was custom-made by Neil Lane.

Tom Brady gave Gisele a four-carat diamond solitaire ring when they became engaged in late 2008. The couple married during a private ceremony in February 2009.

King's beau, director Kyle Newman, presented her with a pavé-set solitaire diamond in April 2007.

Jay Z gave Beyoncé a $5 million, 18-carat Lorraine Schwartz diamond in April 2008.

David Beckham proposed to Victoria Adams with a three-carat marquise-cut diamond.

Will Smith proposed to Jada Pinkett with this emerald-cut diamond in 1997.

Matthew Broderick gave SJP her stunning emerald-cut ring before the couple's 1997 marriage.

When Lady Diana Spencer and Prince Charles became engaged in February 1981, Diana chose a Garrard ring with a 12-carat oval sapphire surrounded by 14 solitaire diamonds.

In 1968 (four years into their first marriage), Richard Burton gave Elizabeth Taylor the Krupp Diamond, a 33.19-carat Asscher-cut jewel. Though not technically an engagement ring, it's one of the most iconic pieces of jewelry of all time.

Frank Sinatra gave Farrow a pear-shaped solitaire diamond ring before their July 1966 wedding.

Taylor's third husband, Mike Todd, gave her this "friendship ring" of 29 karats before their 1957 wedding.

Princess Grace originally received a Cartier eternity band (left) comprised of rubies and diamonds from Prince Rainier III of Monaco, but he soon swapped it for a 10.5-carat Cartier diamond ring.

Joe Dimaggio gave this eternity band, set with 35 baguette-cut diamonds, to Marilyn Monroe at their 1954 wedding.

John F. Kennedy gave Jacqueline Bouvier a custom Van Cleef & Arpels engagement ring featuring a 2.84 carat emerald and a 2.88 carat diamond.

The diamond on Queen Elizabeth II's engagement ring came from a tiara owned by Prince Phillip's mother, Princess Alice of Battenberg.