2015 Russian Grand Prix

The 2015 Russian Grand Prix (formally known as the 2015 Formula 1 Russian Grand Prix; Russian: Гран-при России 2015 года, romanized: Gran-pri Rossii 2015 goda) was a Formula One motor race that took place on 11 October 2015. The fifty-three lap race was held at the Sochi Autodrom. This was the fifteenth round of the 2015 season and marked the second time that the Russian Grand Prix was run as a round of the Formula One World Championship since its inception in 1950.

Lewis Hamilton won the race for the second season in a row, extending his Drivers' Championship lead to 66 points. With Nico Rosberg retiring early in the race, Sebastian Vettel reclaimed second place in the standings for the first time since his round two victory in Malaysia with a second-place finish. Sergio Pérez completed the podium in third for Force India.

Mercedes secured their second consecutive Constructors' Championship, having done so at the same event the previous season.

After the previous year's race showed lower-than-expected tyre degradation, Pirelli opted to supply the yellow-banded soft compound as the prime selection and the red-banded supersoft tyre as the option selection. The previous season's event saw Nico Rosberg complete 52 of 53 laps on the white-banded medium compound on his way to a second-place finish. Even with the softer tyre choice, tyre degradation was not an issue at the event, with drivers able to record fast lap times all through the race on a one-stop strategy.

Roberto Merhi replaced Alexander Rossi for Marussia, in accordance with Rossi's five-race contract that saw him sit out this race and the Abu Dhabi Grand Prix. Jolyon Palmer replaced Romain Grosjean for Lotus for Friday's first free practice session for the tenth time this season.

Fernando Alonso began the weekend's event knowing he would start from the back of the grid due to a number of penalties incurred for changing engine parts. Honda provided him with an upgraded internal combustion engine, which had been designed using the team's last four in-season development tokens. Alonso's McLaren teammate Jenson Button had to continue using the old-specification engine at this race as Honda only had one of the upgraded power units available. However, Alonso used the new power unit only in the first practice session before switching back to the older unit, albeit voicing satisfaction with the performance of the new specification.

Going into the weekend, Lewis Hamilton led the Drivers' Championship with a 48-point advantage over teammate Rosberg, with Sebastian Vettel another eleven points behind in third. Mercedes led the Constructors' Standings on 506 points, 169 points ahead of Ferrari. In third was Williams, another 129 points behind.

Per the regulations for the 2015 season, three practice sessions were held, two 90-minute sessions on Friday and another one-hour session before qualifying on Saturday. However, all three sessions were disrupted and little running took place. During the first session on Friday morning, a spillage of diesel on track prevented the cars from going out on until very late in the session. Eventually, Nico Hülkenberg topped the session for Force India, ahead of his compatriots Nico Rosberg and Sebastian Vettel. Since water was used to clear the surface, the first laps were run on intermediate tyres by most drivers, with both Williams cars being equipped with full wet tyres, but Valtteri Bottas spun on them entering the pit lane. Later, the track dried enough to use slick tyres, Fernando Alonso being the first to do so. Due to the limited running, the last minutes were busy with most cars out on track. Marcus Ericsson however was confined to the sidelines as he stopped with an engine problem. As Lewis Hamilton spun on his last timed lap, he needed to settle for seventh fastest.