Any thoughts that Mercedes-Benz would be challenged for the 2015 Formula 1 World Championship were dispelled from the first race of the season. Lewis Hamilton and Nico Rosberg locked out the front row at 15 of the 19 races and finished 1-2 on 12 occasions. The Englishman began the campaign in dominant fashion – qualifying on pole position for 10 of the first 11 races and was soon in control of the championship. Victory in the wet United States Grand Prix was his 10th of the season and clinched a third world title with three races to spare. That decided, momentum within the team swung to Rosberg who won those last three GPs as he finished as runner-up for a successive season.
Despite being unable to challenge Mercedes for the title, Ferrari made tangible progress in 2015. With increased power from its V6 turbo and Sebastian Vettel thriving in his new environment, the team finished as championship runners-up thanks to the German's three victories. Kimi Räikkönen was a distant fourth in the drivers' standings after being overshadowed by his new team-mate and having crashed into compatriot Valtteri Bottas on a couple of high profile occasions.
Williams retained third in the World Championship with both Bottas and Felipe Massa visiting the podium on a couple of occasions. Their cause was aided by poor seasons for the better funded Red Bull and McLaren teams. The former spent much of the season in open dispute with engine supplier Renault as owner Dietrich Mateschitz appeared to question continued involvement in the sport. Newcomer Daniil Kvyat narrowly beat Daniel Ricciardo to seventh in the standings with both drivers scoring a best finish of second. McLaren switched to Honda engines but the Japanese manufacturer's new power train proved off the pace and unreliable. With drivers Jenson Button and Fernando Alonso, world champions both, struggling to conceal growing frustration at the lack of progress, the team finished in an embarrassing ninth overall.
Force India also benefited from McLaren's travails as it improved to fifth in the standings with Sergio Pérez finishing third in Russia. Lotus's 2015 campaign was overshadowed by continuing financial woes and protracted take over talks with Renault. Boosted by a single season with Mercedes engines, Romain Grosjean finished a welcome third in Belgium in his final season with the Enstone-based concern.
Scuderia Toro Rosso fielded rookies Max Verstappen and Carlos Sainz jr but, like the senior Red Bull squad, was restricted by development and reliability of its Renault power train. However, both youngsters did enough to impress and Verstappen was named as FIA Rookie of the Year after twice finishing fourth.
The opening weekend of Sauber's season was dominated by legal action from former reserve driver Guido van der Garde who claimed to have signed a valid race contract for 2015. That dispute was eventually settled out of court as Felipe Nasr and Marcus Ericsson finished the Australian GP in the points – the team's first for a year. The rest of the campaign was spent in the lower echelons of the midfield as Sauber finished eighth in the championship.
The restructured Manor Marussia team emerged from administration to bring up the tail of the 2015 field. Forced to use year old chassis and Ferrari engines to save money, it finished no race higher than 12th but mere participation was enough to secure a lucrative 10th (and last) overall.