The hosts did the damage during a devastating first-half display which saw Paco Alcacer and Lionel Messi get on the scoresheet, with Barca also hitting the woodwork three times in the opening 45 minutes.
That allowed Ernesto Valverde's side to take their foot off the pedal in the second half as they cruised to victory, taking them another step closer to a seventh title in 10 years.
Find out how all of the action unfolded courtesy of Sports Mole's minute-by-minute updates below.
This will be a particularly special occasion for Ernesto Valverde as he takes on the team he has previously played for and managed, and victory would take the Barca boss another step closer to clinching the title in his first season at the club.
We will take a close look at both clubs shortly, but first let's check out the team news...
Well, the headline as far as Barcelona are concerned is that Luis Suarez misses out this afternoon, with the Uruguayan serving a suspension for this match. His absence hands a rare opportunity to Paco Alcacer, who scored the last time Athletic visited the Camp Nou but does not get many chances to start in the league.
Indeed, this will be only Alcacer's seventh league start of the season, and he has big shoes to fill if he is to make up for the loss of Suarez today.
That left Messi looking very fresh in midweek, and he was at his best to score two goals and register an assist in their 3-0 win over Chelsea, inspiring his side into the quarter-finals of the Champions League. He has 24 La Liga goals to his name this season too, so will once again be Barca's main dangerman today.
Not many would have expected it to take until March for the Frenchman to open his account following such an expensive move last summer, but injuries have played a major part in that and Dembele will now be keen to push on and score plenty more goals for the Catalan outfit going forward.
Barcelona stalwarts Andres Iniesta and Sergio Busquets both miss out - the former dropping to the bench and the latter missing due to a toe injury which is expected to keep him sidelined for three weeks - as Coutinho and Paulinho both come into the side.
It will be interesting to see how they do that today as the midfield three all like to get forward whenever possible. Coutinho will certainly not be in the holding midfield role, while Paulinho's late surges into the box have been a feature of Barca's season so far, which could leave Rakitic as the one needing to be the most disciplined today.
Aduriz is the club's top scorer in La Liga this season with eight goals, but he also sat out against Leganes last weekend so it is not a huge surprise that he returns to the subs today. Williams, however, was expected to be an important figure in the team today due to his threat on the counter-attack, so his omission is surprising.
Raul Garcia is expected to be their main goal threat today then, having netted seven times already this term, although Merino leading the line will also hope to see a few chances fall his way against a Barca defence that has been very impressive this season.
There are just two changes to the team which faced Leganes in their most recent La Liga game as Lekue and Merino start in place of Cordoba and Williams.
The football they have been playing under Valverde is not quite as easy on the eye as the glory years under Pep Guardiola, but they are still picking up results and it would take an unlikely and dramatic collapse for them to fail to win the title for the seventh time in the past 10 years this season.
Just as satisfying for the Barca fans will be their 15-point lead over bitter rivals Real Madrid, who are also not in action until later today. Los Blancos - who are the defending champions, remember - could begin their match against surprise package Girona this evening a full 18 points adrift of the La Liga leaders.
Barca are the only team in Europe's top five leagues yet to lose a game this term, and stretching back to last season they are now unbeaten in their last 35 top-flight games, winning 29 of those in a run which goes back to April 8 of last year.
Only Atletico Madrid have managed more clean sheets and conceded fewer goals, with the partnership of Pique and Umtiti at the back proving to be Barca's most reliable in quite some time.
Indeed, that Espanyol defeat is Barca's only reverse in their last 45 matches across all competitions, the most recent of which saw them progress into the quarter-finals of the Champions League at Chelsea's expense in midweek. Having also reached the final of the Copa del Rey and boasting such a commanding lead at the top of the table, yet another treble for Barca looks increasingly likely.
What's more, Barca have now kept four clean sheets in their last five home outings and an impressive 15 throughout the campaign from only 22 matches in front of their own fans.
Valverde's side have dropped just four points at the Camp Nou so far this term to boast the best home record in the division as one of only two teams - alongside Atletico - yet to taste home defeat. Barca also have the best attacking record in the division when it comes to home games, while only Atletico have conceded fewer on their own patch.
Valverde spent six years as an Athletic Bilbao player - incidentally after joining from Barcelona - going on to make 170 league appearances for the club. He then went on to spend six years with the club as manager over two spells - and an additional year as assistant - including four seasons at the helm prior to his 2017 departure.
Not since 2008-09 have Athletic finished lower than 12th and, while they are still five points closer to the top six than they are to the relegation zone, it has been a very disappointing campaign for them so far.
The Spanish outfit had plenty to do after losing the away first leg 3-1, but they then fell two goals down in Thursday's second leg at home to completely kill the tie off. Williams did pull a consolation goal back, but ultimately they went down 5-2 on aggregate.
Athletic had won five and lost just one of their 10 matches prior to that recent record, so it is an alarming drop off in form which has seen them sink into the bottom half of the table.
A victory this afternoon, however unlikely it may seem, would see them string together successive league wins for the first time since either side of the winter break and only the third time all season, having beaten Leganes last time out.
Another defeat this afternoon would see them fall to four in a row across all competitions for the first time in more than a year, and also four La Liga away defeats on the spin for the first time since October 2014. Athletic have failed to even score in their past three defeats, so it is looking pretty bleak for them today.
As if that wasn't enough, Athletic have also lost their last eight away games and 20 of their last 21 against Spain's big three.
It is hard to see past a Barcelona win this afternoon, with the hosts in such good form and Athletic far from it. Barcelona haven't been blowing teams away with regularity this season, so this won't quite go into the realms of a rout, but it should still be a comfortable victory.
SPORTS MOLE SAYS: Barcelona 3-0 Athletic Bilbao
Indeed, Barca have also won eight of the last nine meetings across all competitions, and in La Liga alone they are on a dominant eight-game winning run against Athletic Bilbao.
The most recent of those meetings came in October, when Lionel Messi and Paulinho were on the scoresheet in a 2-0 victory.
Since then they have drawn four and lost 16 of their 20 visits, the most recent of which saw Paco Alcacer, Lionel Messi and Aleix Vidal all score in a 3-0 win for Barcelona last February.
BARCELONA STARTING XI: Ter Stegen; Sergi Roberto, Pique, Umtiti, Alba; Rakitic, Paulinho, Coutinho; Dembele, Alcacer, Messi
ATHLETIC BILBAO STARTING XI: Arrizabalaga; Lekue, Nunez, Martinez, Saborit; Benat, San Jose, De Marcos, Garcia, Susaeta; Merino
It all looks far too easy for the hosts as Messi pokes the ball out to Alba, who immediately plays a low ball into the box. Alcacer is left completely unmarked and just steers his finish into the far corner to give Barcelona another quick start.
Dembele's pass inside finds the Argentine in a bit of space right on the edge of the box, and he takes a touch before drilling a pinpoint finish into the bottom corner past Kepa. That could well be game over already.
It has been one-way traffic from the very first whistle here at the Camp Nou, with Barca scoring twice and also hitting the woodwork on three occasions - not to mention the saves made by Kepa.
Messi played the ball out to Alba on the left side and, as has been the case on numerous occasions this season, Alba played a low ball into the box. Alcacer was left unmarked in the middle, and he applied a simple finish to steer the ball into the bottom corner.
Dembele played the ball in to the Argentine, who was left in too much space right on the edge of the area. Messi was able to take a touch before arrowing a pinpoint finish into the bottom corner.
Barcelona have created shooting opportunities almost at will - which is why it is surprising that they only have a two-goal lead - but if it is a similar story in the second half then Athletic could be on the end of a hefty defeat here.
Goals from Paco Alcacer and Lionel Messi in the first half were ultimately enough to wrap up another three points, taking Barca 11 points clear of second-placed Atletico Madrid and 18 above Real Madrid. A seventh title in 10 years is within their grasp now!
Thank you very much for joining Sports Mole as Barcelona cruise past Athletic Bilbao to take another step towards the title. I will leave you with our match report, and be sure to stick around for any reaction too.
From me, though, it is goodbye for now!