Check out my rankings within each division by clicking on the links below. If there is a lineal champion in a weight class, he is ranked No. 1.
Who is the best fighter regardless of weight class? See ESPN's pound-for-pound rankings.
For a list of the current champions in all weight classes, click here.
Note: Results through April 10. In an effort to provide the most up-to-date rankings, ESPN.com's division-by-division boxing rankings will be updated every Tuesday.
More divisional rankings
Mediano - Junior mediano - Welter - Junior welter
Ligero - Junior ligero - Pluma - Junior pluma
Gallo - Junior gallo - Mosca - Junior mosca/Paja
WELTERWEIGHT DIVISION (UP TO 147 POUNDS)
1. Manny Pacquiao (59-6-2)
After a brief retirement following a one-sided decision win against Timothy Bradley Jr. in April 2016, and subsequent election to the senate in the Philippines, Pacquiao returned on Nov. 5 and ran roughshod over Jessie Vargas. Pacquiao scored a second-round knockdown and won a unanimous decision against a man 10 years younger than he is to regain a welterweight world title in an excellent performance. Top Rank promoter Bob Arum tried to line Pacquiao up to defend against Jeff Horn (16-0-1) in Australia on April 22, but Pacquiao instead chased a deal for a fight in the United Arab Emirates against former junior welterweight titlist Amir Khan. But when the Khan fight went nowhere, the fight with Horn was finalized. Pacquiao will head to Horn's hometown of Brisbane, Australia, for the title defense.
Next: July 1 vs. Horn
2. Keith Thurman (28-0)
The hard-hitting and exciting Thurman made his third title defense in a rousing battle with former titleholder and good pal Shawn Porter on June 2016 at Barclays Center in Brooklyn, New York. The fight was the headliner on CBS in prime time -- the network's first prime-time card since Muhammad Ali-Leon Spinks I in 1978 -- and Thurman and Porter delivered a tremendous fight-of-the-year candidate, which Thurman, the bigger puncher and better defender, won by close decision, 115-113 on all three scorecards. Thurman returned to Barclays Center and CBS on March 4 and claimed a well-deserved split decision against Danny Garcia to hand him his first loss and unify world titles in a heavily-anticipated match.
3. Kell Brook (36-1)
Brook was close to a deal to unify belts against Jessie Vargas, but, when that deal went south, Brook and promoter Eddie Hearn pulled a huge surprise as Brook signed to move up two weight classes to take a shot at unified middleweight titlist Gennady Golovkin in September. It was an exciting fight with an electric crowd in London, but Brook got stopped in the fifth round when his corner threw in the towel as he was getting battered. Brook, who suffered a broken right orbital bone and had surgery, will be back this spring, but, when the prospect of an all-British megafight with Amir Khan went south, Brook elected to make his mandatory defense against dangerous Errol Spence Jr. (21-0).
Next: May 27 vs. Spence
4. Timothy Bradley Jr. (33-2-1)
In his first fight with trainer Teddy Atlas, Bradley looked fantastic as he wiped out an out-of-shape Brandon Rios in a ninth-round knockout victory in November. But Rios is no Manny Pacquiao, so when Bradley and Pacquiao met for the third time on April 9, it was a different story. Bradley got knocked down twice and lost a clear unanimous decision -- 116-110 on all three scorecards -- in what Pacquiao said would be his final fight. Bradley officially is 1-2 against Pacquiao but most of the world agrees he should be 0-3. He can't beat Pacquiao, but he would probably beat many other top welterweights.
5. Danny Garcia (33-1)
Garcia vacated his unified junior welterweight belts and moved up to welterweight in August 2015 and mowed down faded former titlist Paulie Malignaggi in nine one-sided rounds. On Jan. 23, Garcia headlined the debut of Premier Boxing Champions on Fox in prime time and although he struggled early against Robert Guerrero, he came on strong in the second half of the fight to win a vacant belt. His return came Nov. 12 at home in Philadelphia in a horrific mismatch with Samuel Vargas in a nontitle fight. Garcia abused Vargas en route to a seventh-round knockout, paving the way to a unification fight with Keith Thurman, who won a split decision to unify world titles on March 4 in a big-time fight.
6. Amir Khan (31-4)
England's Khan, a former unified junior welterweight titlist, was unable to land fights with either Floyd Mayweather or Manny Pacquiao, who each strongly considered fighting him but went in other directions, so he jumped at the chance to challenge middleweight champion Canelo Alvarez on May 7. Khan, who had won three fights in a row against good opposition since moving up to welterweight (Luis Collazo, Devon Alexander and Chris Algieri), moved up again to meet Alvarez at a catchweight of 155 pounds. Khan looked excellent early and gave Alvarez problems with his speed and movement, but the more powerful Alvarez eventually connected with a mighty right hand that knocked Khan out cold in the sixth round. Talks for a possible big all-British showdown this summer against countryman Kell Brook fizzled when Khan ridiculously demanded 70 percent of the money and a spring or summer fight with Manny Pacquiao also went down the tubes.
7. Shawn Porter (26-2-1)
Porter didn't look so good as he lost a majority decision and his world title to England's Kell Brook in August 2014 but then he won his next two fights, including a big one against former titleholder Adrien Broner, whom he took to school in June 2015. After a year layoff, Porter returned on June 25 to challenge pal and world titleholder Keith Thurman in one of the best matches that could be made in boxing. And they more than lived up to the expectations with a sensational action battle, which Porter lost by the closest of margins, 115-113 on all three scorecards. Porter wanted a rematch but was denied and will instead take on former titlist Andre Berto (31-4) in a title eliminator to become one of Thurman's mandatory challengers.
Next: April 22 vs. Berto
8. Errol Spence Jr. (21-0)
Spence was the best pro prospect from the 2012 U.S. Olympic team. He has lived up to the hype so far in the pros, as he has looked impressive fight in and fight out. Spence, who looks every bit like a future world titleholder, was sensational April 18 in the main event of a Premier Boxing Champions card on NBC, as he destroyed junior welterweight titlist Chris Algieri, by far his best opponent. He dropped Algieri three times in a fifth-round knockout win. In his next fight, on Aug. 21, Spence destroyed Italy's Leonard Bundu by brutal sixth-round knockout in a title eliminator to earn a mandatory shot at titleholder Kell Brook (36-0), whom he will travel to England to face.
Next: May 27 vs. Brook
9. Jessie Vargas (27-2)
Vargas, a former junior welterweight titleholder, moved up in weight and challenged Timothy Bradley Jr. for a vacant belt in June 2015. Although Vargas lost a unanimous decision, he nearly knocked Bradley out in the final seconds of the fight. Vargas didn't get the rematch he wanted but instead got a chance to face Sadam Ali on March 5 on HBO for the belt Bradley vacated and he made the most of his opportunity. Vargas looked sharp in an impressive ninth-round knockout victory. He was supposed travel to England to fight Kell Brook in a unification match in September but the deal fell apart and he wound up with an even bigger fight -- a high-profile defense against unretiring Manny Pacquiao on Nov. 5. Vargas gave a great effort but he was knocked down and outclassed in a decision loss.
10. Felix Diaz (19-1)
Diaz, who won an Olympic gold medal for the Dominican Republic in 2008, suffered his only defeat by highly controversial majority decision to former junior welterweight titlist Lamont Peterson in October 2015, but bounced back with an impressive performance in a decision win against then-unbeaten Sammy Vasquez in July. Diaz hoped for a shot at unified junior welterweight champion Terence Crawford in December, but his efforts to land that fight were simply ignored by Crawford's team. Instead, he stayed busy with a seventh-round knockout of Levis Morales in a Dominican Republic homecoming fight on Dec. 16. Finally, he will get a shot at Crawford (30-0) on HBO.
Next: May 20 vs. Crawford