Kubica, who has not taken part in a grand prix for eight years following the horrific rally crash which left him seriously injured, joins Englishman George Russell at the British team in 2019.
The 33-year-old Polish driver has competed in a series of practice sessions for Williams this year and his promotion to their race team for next season was announced in Abu Dhabi, the venue of his last race back in 2010, on Thursday.
Kubica, whose right arm was partially severed in the rally crash in Italy in February 2011, hailed his return to F1 as “one of the greatest achievements” of his life, admitting the road back to the pinnacle of the sport had seemed “almost impossible”.
He said: “Firstly, I would like to thank everyone who has helped me during what was a difficult period of my life over these last few years.
“It has been a challenging journey to make it back to the Formula One grid, but what seemed almost impossible is now beginning to feel possible, as I am excited to be able to say that I will be on the Formula One grid in 2019.
“For sure, it has been a long road to get to this point, but as that challenge now comes to an end with this announcement, a new challenge begins working with Williams on track.
“It will not be easy, but, with hard work and dedication, both George and myself will work together to try and help the team get in better shape to move further up the grid. This year has been tough, but I have learnt a lot, and I’d like to thank (team principal) Sir Frank (Williams) and (deputy team principal) Claire (Williams) for this opportunity.
“Being back on the F1 grid next season will be one of the greatest achievements of my life and I’m sure with hard work and commitment we will be able to help motivate the team to achieve good things together. Thank you again to everyone who has supported me and believed in me.
“I will finally be back on the grid behind the wheel of an F1 car and I cannot wait to get back racing.”
Claire Williams said the team had been “immensely impressed” with Kubica and praised his “strength of character and tenacity to return”.
“During this season his commitment to the team and the work he has put in behind the scenes has been unwavering and he has become an established and much respected member of the Williams team,” she added.
“He has a level of determination that is remarkable to see and he truly embodies the Williams fighting spirit.”
Kubica’s injuries brought a dramatic halt to an F1 career that had already yielded one grand prix victory and seen him hailed as one of the finest talents on the grid.
His slow journey back to F1 began when he returned to rallying before he took part in a series of tests for his former team, Renault, last year.
Kubica then drove for Williams at last year’s post-season test in Abu Dhabi, but the British team opted to take on the Russian rookie Sergey Sirotkin ahead of the Pole.
Kubica was, however, signed to the team as a reserve driver and has been an ever-present at the races this year.
He now replaces Sirotkin and will bring much-needed experience to a team rooted to the foot of the constructors’ championship after one of the worst seasons in their history.
He is also believed to be bringing a substantial boost to Williams’ financial muscle via PKN Orlon, a major Polish oil refiner.
After 20 races over eight grueling months, Formula One heads to Abu Dhabi for the concluding grand prix of the season.
Here, we take a look at five key talking points ahead of Sunday’s race at Yas Marina Circuit.
Lewis Hamilton was given a champion’s welcome when he returned to the Mercedes factory for the first time since sealing his record fifth championship at the Mexican Grand Prix.
The 33-year-old was greeted with a guard of honour by the 900-strong staff at the Mercedes’ headquarters in Northamptonshire following the team’s fifth successive constructors’ championship victory in Brazil.
The team’s latest success means they are now level with Ferrari on five consecutive wins with no team having ever lifted six titles.
The Briton will bid to see out the championship with his 11th win of the season in Abu Dhabi, a track where he has tasted victory on three occasions.
VETTEL PLAYS FOR PRIDE
With both the drivers and constructors championships settled, there is only pride to play for Sebastian Vettel at Yas Marina Circuit on Sunday.
Vettel, who led this year’s championship until round eleven in Germany, will be hoping to finish his season on a positive note in the UAE capital.
Following his sixth place finish at the most recent Brazilian Grand Prix, Vettel has struggled in the second half of the season, while Hamilton has excelled.
The 31-year-old is a three-time winner at Yas Marina but has not won at the track since joining Ferrari in 2014. Could this be the year he rediscovers some of that old magic?
ALONSO’S FINAL RACE
Double world champion Fernando Alonso will bring the curtain down on his storied F1 career in Abu Dhabi this weekend.
The 37-year-old is nearing the end of his 17th season in the sport and will race in the Indy 500 next year as he attempts to secure the ‘Triple Crown of Motorsport’.
The Spaniard, a double Monaco Grand Prix winner in 2006 and 2007, won the Le Mans 24 Hours with Toyota in June this year and is tenth in the drivers’ championship standings.
His glittering career has included 32 wins, 22 pole positions, 97 podiums and world championship triumphs in 2005 and 2006, although he has not finished on the podium since joining McLaren in 2015.
With nine top-10s this campaign, Alonso will be bidding to bow out with a formidable finish.
RICCIARDO’S LAST CHANCE
Daniel Ricciardo has emerged as one of the sport’s most likeable figures – but he has looked low on confidence since winning the Monaco Grand Prix way back in May.
At that point of the season, Mercedes and Ferrari were circling for his signature, but he ended up signing a long-term deal with Renault – a team who have not secured a podium since the Malaysian Grand Prix in 2011.
There is no guarantee the Australian will slot straight into the Renault and challenge the big three, especially with his teammate Nico Hulkenberg producing some solid performances this season and unable to threaten a top four finish.
Without a podium since May, adding to his eight retirements, this could potentially be the last chance for 29-year-old Ricciardo to walk on top of the steps and celebrate a top three finish.
MORE EXCITEMENT NEEDED
Formula One’s season-ending fixture has come under criticism in recent years for its lack of action and failure to deliver an exciting race.
Despite a spectacular setting at Yas Marina, drivers have felt the track isn’t challenging enough to be the final race on the calendar.
Hamilton called for changes to be made to the 3.4-mile circuit last year while Kimi Raikkonen and Max Verstappen labelled it ‘boring’.
The Yas Marina circuit joined the F1 calendar in 2009 and has acted as the season finale venue for every season expect 2011, 2012 and 2013.
Valtteri Bottas became the fifth different winner of the race by converting his pole position into victory last season, while Hamilton and Vettel share three wins each.
Two-time world champion Alonso is leaving Formula 1 after the season finale and has said he does not plan to return.
To mark the occasion, McLaren have unveiled a new livery on Alonso’s MCL33, which includes colours of the Spaniard’s helmet – blue, yellow and red – in the orange and black livery.
The colours have been emblazoned across the car’s engine cover, while there is also a special ‘FA’ logo on the top and sides of the cockpit.
“We want his last grand prix to feel special in every way, and this was just one of the ways we could reflect that,” said McLaren CEO Zak Brown.
“We worked closely and collaboratively with Fernando, and then with the FIA and Formula One to make the change for this one race, and they were all hugely supportive of the move.
“Hopefully, this will give Fernando’s fans a little something extra to look forward to at what is bound to be an especially emotional weekend.”
It will be the first time McLaren enter a race with a one-off livery since bringing a yellow-branded car for Keke Rosberg at the 1986 Portuguese GP.
Alonso who joined McLaren in 2015, will remain with the team but no longer as an F1 driver. Instead, he will lead McLaren’s bid to win next year’s Indianapolis 500 as he goes for motorsport’s unofficial ‘Triple Crown’ of winning the Indy 500, the Monaco Grand Prix, and the Le Mans 24-hour race.
But with his F1 career set to come to an otherwise underwhelming end – the Spaniard, widely regarded as one of the best drivers of his era, has not won a race since 2013, when he was with Ferrari, as McLaren have struggled to give him a competitive car, and a low points finish is all he can reasonably expect in Abu Dhabi – this weekend’s one-off livery will at least be a memorable way to send him off.