UPDATE: Mahershala Ali won Best Supporting Actor for Green Book.

Last Updated: January 30, 3019

Now that the 2019 Oscar nominations have been set, it's time to take a look at who has the best chances of winning Best Supporting Actor. Earlier this week, the Screen Actors Guild became the latest Academy precursor to hand out their awards, shedding further clarity on what has been a twisty and unpredictable race so far. For much of the season, many of the major categories remained up in the air, with several viable contenders feeling they had a great shot to win.

But now that the Academy ceremony is a little under a month away (as of this writing), clear frontrunners are starting to emerge from the pack. Best Supporting Actor is one field that seems like it's already locked up, but there are still four men hoping to garner enough support from viewers to pull off an upset. Here, we rank the five Supporting Actor nominees in order of most likely to least likely to win.

Related: Screen Rant's Best Actor 2019 Predictions

Mahershala Ali - Green Book

A previous winner in this category for his tender performance in Moonlight, Ali is back in contention again for his turn in Green Book. Peter Farrelly's film sees the actor portray Dr. Donald Shirley, an African-American classical pianist who embarks on a concert tour in the deep South. While the movie (controversially) focuses more on Viggo Mortensen's Tony "Lip" Vallelonga, the script doesn't completely shortchange Shirley and gives Ali some compelling layers to explore. Green Book plays up the idea that Shirley was torn between two worlds; he wasn't fully accepted by the white community due to the color of his skin, and the black community also ostracized him for not being "black" enough. Ali was the perfect straight-man to Mortensen and delivered some of the best work of his career.

Ali's efforts haven't gone unnoticed by awards voters and he seems poised to run away with his second career Oscar. He has already won Best Supporting Actor from the Golden Globes, SAG awards, and the Critics' Choice Awards - a hat trick that essentially leaves his competition in the dust. The only times since 2007 that the SAG and Oscar winners did not overlap were 2012 and 2015. This means Ali has history very much working in his favor and fans of his should feel comfortable picking him in their Oscar pools. Despite all the backlash surrounding it, Green Book remains a top contender for Best Picture, and if it can't take home the top prize, the Academy may still want to reward the film by commemorating Ali's wonderful performance.

Sam Elliott - A Star is Born

A veteran whose career dates back to the late 1960s, Sam Elliott has as impressive a filmography as anyone in Hollywood, and only now has earned his first Oscar nomination. He does have two Golden Globe nods to his name, both for TV performances in Conagher and Buffalo Girls. One narrative the Academy is particularly fond of is giving overdue names the recognition they deserve, and Elliott would certainly fit the bill there. In Bradley Cooper's remake of A Star is Born, Elliott played Bobby, brother to Cooper's Jackson Maine. He is undeniably great in the film, as the dynamic between the two siblings leads to some emotionally powerful moments. In some scenes, Elliott doesn't even need to speak lines of dialogue to convey his character's feelings.

Related: A Star is Born's Ending Is Bad (And Always Has Been)

Save for an odd snub at the Golden Globes, Elliott picked up nods from all the necessary Oscar precursors. In addition to winning Best Supporting Actor at the National Board of Review, Elliott also received nominations from SAG and Critics' Choice. However, his losses at those last two are key, since he'll have to overcome sizable odds in order to rise above the favorite, Ali. And while A Star is Born did score eight Oscar nominations overall, its performance in the precursors points to a lack of overly passionate fans that will look to award it wherever they can. The film entered Oscar season as the presumed frontrunner for Best Picture, but its chances have taken a huge hit over the past couple of months. Because of that, Elliott may not secure enough votes to take home the Oscar. If he had better luck in other races, then it'd be a different story.

Adam Driver - BlacKkKlansman

An extremely gifted actor who rose to more prominence following his turns as Kylo Ren in the Star Wars sequel trilogy, Driver continues to build an interesting career by working with some of the industry's top filmmakers. In his latest project, Driver collaborated with Spike Lee on BlacKkKlansman and played Flip Zimmerman, the white police officer who partners with John David Washington's Ron Stallworth during an investigation into a local chapter of the Ku Klux Klan. Flip is a very important role; not only does he serve a necessary function in the plot (he poses as Ron for in-person meetings with "the organization"), but his presence highlights the film's themes and how the KKK's hatred wasn't relegated to just African-Americans. As Flip, Driver has to portray a man conflicted by his Jewish heritage and how the Klan's policies affect him on a personal level.

Driver is unsurprisingly great in BlacKkKlansman, which was a key player on the awards circuit. In addition to his first career Oscar nomination, he also scored nods from the Golden Globes, SAG awards, Critics' Choice Awards, Gotham Awards, and Film Independent Spirit Awards. All of those accolades are great and well-deserved, but they likely will not translate into an Academy Award win. Like Elliott, Driver has spent much of this awards season watching Ali take home Best Supporting Actor trophies, so it looks like he'll have to wait until next time. It feels like Driver will win an Oscar one day, but in 2019, he doesn't have the big wins nor the "overdue" status to get across the finish line.

Richard E. Grant - Can You Ever Forgive Me?

Another esteemed veteran with a decades-long career, Grant has largely been ignored by awards voters so far. That changed with Can You Ever Forgive Me?, in which the actor plays Jack Hock. Jack is a close friend to Melissa McCarthy's Lee Israel, who takes part in Lee's forgery scheme to get rich quick. In the film, Grant commands viewers' attention as a devilish scoundrel, playing off McCarthy with gusto. He's an absolute delight to watch and a big reason why Can You Ever Forgive Me? works as well as it does. For his efforts, Grant earned his first career Oscar nomination.

Related: Read Screen Rant's Can You Ever Forgive Me? Review

Also being recognized by the Golden Globes, SAG awards, and Critics' Choice Awards (plus dozens of other nominations from smaller critics associations), it's great to see Grant get this kind of love. And as wonderful as it would be to see him win, the odds of that happening are quite low. Since Grant has not won any of the main Oscar precursors, he will likely have to be happy with his nomination and hope another juicy role comes his way soon. In addition, Can You Ever Forgive Me? has been a minor player on the circuit, with only three Oscar nominations total to its name (and it wasn't named a Best Picture candidate). Grant is undeniably great in the film, but his turn isn't transcendent enough to soar above the rest.

Sam Rockwell - Vice

The fan-favorite character actor finally got the due many felt he deserved last year with his Oscar-winning turn in Three Billboards Outside Ebbing, Missouri. Rockwell finds himself back in the mix again thanks to his performance as George W. Bush in Adam McKay's Vice. Out of the dark comedy's star-studded ensemble, Rockwell didn't have the most screen time, but still managed to leave an impression. In addition to this (somewhat surprising) Oscar nomination, he was also nominated for the Golden Globe and BAFTA in Best Supporting Actor. Channeling his natural charm and charisma, Rockwell was able to beat out the likes of Timothée Chalamet and Michael B. Jordan for another shot at Oscar glory.

However, it's a good thing for Rockwell that he won last year. Out of the five Academy nominees, he had the worst luck on the precursors, including a snub at SAG. Since those guild awards started in 1994, only twice has the Oscar winner not been nominated for SAG. That statistic puts Rockwell at a distinct disadvantage. Additionally, it's incredibly rare for an actor to win Oscars in consecutive years. The last time that happened was when Tom Hanks pulled off powerhouse performances in Philadelphia and Forrest Gump in 1993 and 1994, respectively. Rockwell is a nice presence as Bush in Vice, but the part isn't sizable enough for him to rise above the competition.

More: Screen Rant's Best Director 2019 Predictions