The Formula One season would include five different world champions to enter a race ahead of the new season. Aside from reigning champion, Lewis Hamilton there was also Sebastian Vettel, Jenson Button, Kimi Räikkönen and Fernando Alonso. The season would take place over five race continents and 20 countries with over 200 "television territories" to cover the races.
Marussia are expected to either revert back to the original team name of Manor or change their name to something completely different. A planned auction on 21 January 2015 was postponed on 19 January to allow talks regarding a rescue package to be furthered. On 4 February, it was confirmed by administrators that Marussia would go out of administration on 19 February 2015 when there was new investment that was secured to save the team, along with an agreement on a CVA with creditors. It was later reported in the same month that the team's entry fee for the season had been paid, giving more hopes for the team to compete in 2015. The team later confirmed that they will take part in the Australian Grand Prix.
It was announced on 5 February 2015 that Caterham's assets were set to be sold by their administrators starting on 11 March 2015, only four days before the Australian Grand Prix, and the FIA's updated entry list on 27 February 2015 excluded the team.
Sebastian Vettel left Red Bull at the end of 2014 after 15 years with the team and the junior development program to join Ferrari after Alonso left. Red Bull promoted Daniil Kvyat to the vacated seat.
Marcus Ericsson left Caterham, after it went into administration, to join Sauber for 2015, and will be partnered with Williams test driver and GP2 driver Felipe Nasr. These deals left Adrian Sutil and Esteban Gutiérrez without a drive. Gutierrez later joined Ferrari as a test driver, while Sutil joined Williams as a test and reserve driver.Giedo van der Garde won legal challenges towards Sauber in Swiss and Australian courts. The latter made an order to the team to let him race in the Australian Grand Prix. However, he later dismissed the ruling so to aim at getting a new permanent solution for another part of the season.
Toro Rosso's lineup is completely different this year with two new drivers. They are Max Verstappen, who finished third in the 2014 FIA European Formula 3 series and is set to become the youngest driver to join the grid at 17 years old, and will be alongside the 2014 Formula Renault 3.5 Series champion Carlos Sainz, Jr., son of two-time rally champion Carlos Sainz. As a result, Jean-Éric Vergne was left without a drive and went to compete in Formula E, and later joined Gutiérrez as a Ferrari test driver.
The Mexican Grand Prix returned to the calendar after a 23-year absence, taking place towards the end of the season. To make the circuit suitable for the sport's return, it was substantially reconfigured.
The German Grand Prix was intended to be switched back to the Nürburgring after the 2014 race at the Hockenheimring as per the agreement between the two circuits. However, the Nürburgring was not included on the provisional calendar. In January 2015, it was announced by Formula One CEO Bernie Ecclestone that the race will continue to be held at Hockenheim, but it was quickly reported by circuit officials that there is no contract for 2015 yet Later, Ecclestone stated of doubting that the Grand Prix would take place. It was eventually confirmed not to take place at the Hockheimring due to its owners not being able to get prepared, With the Nürburgring also unable to host it, the German Grand Prix was removed from the calendar on 20 March 2015.
Unlike 2014, drivers could only use up to four power units instead of five. During the season, the FIA allowed new power unit manufacturers to use a fifth power unit, taking Honda as an example.
Engine development rules that were introduced in 2014 were changed, as the manufacturers would be able to perform half of the development from 2014. It will be halved a second time in 2016.
After "ugly" nose designs were objected in 2014, it was announced that the noses for 2015 would be lower, preventing a low cross section, although they were required to be tapered to the point of a fixed linear rate, which would see more gradual shapes by outlawing the dramatic finger shapes that were used in 2014. Additionally, the more exotic designs were banned, including the "twin-tusk" design used on the Lotus E22, meaning that the nose design was required to be symmetrical and consistent with the car's centreline.
The cars' minimum weight was brought up to 702 kilograms (1,548 lb).
FRIC (Front-and-Rear Interconnected) suspension systems' ban had been formalised after being implement during 2014. It was stated by the regulations that the front and rear suspension would need to be designed in a way that any performances' changes had to result directly from any change of the load that had been applied to them individually.
The survival cell's anti-intrusion panels were extended up to the cockpit's rims and along the side of the driver's head.
Due to Marussia and Caterham having financial struggles in 2014, the use of cars from 2014 was approved by the FIA, providing that teams had been showing cause and getting separate dispensations to take part with their old cars. However, a request made by Manor to use the MR03 was rejected on February 5, 2015, although there was no disposition granted because that all other teams have to do unanimous agreements, and there was no achievement. Williams also had votes for Manor to use their 2014 car. On 20 February, Maurizio Arrivabene announced that Ferrari would supply Manor with their 2014 engine after a recent meeting of the F1 Strategy Group gave a negative vote to use the 2014 chassis.
The partial ban on pit-to-car communication that was introduced in the previous year's Singapore Grand Prix was extended, including a blanket ban which has sharing data that was technical between the team and driver, like settings on fuel consumption that were specific.
Double points were excluded from the final event of the season.
After a report's recommendations for Jules Bianchi's crash in the 2014 Japanese Grand Prix, the Australian, Malaysian, Chinese, Japanese and Russian Grands Prix started an hour earlier than in 2014, so to not start within four hours of sunset.
After Jules Bianchi's accident in the 2014 Japanese Grand Prix, the virtual safety car (VSC) was introduced. Drivers needed to slow down to the speed shown on their steering wheel's display. It could be started if double waved yellow flags were required on parts of a circuit where an accident had occurred. However, the procedure's circumstances were not as such to the real safety car's warrant deployment.
Rather than waiting for lapped cars to catch up to the end of the pack before the safety car came into the pits, the safety car would come back to the pits at the end of the next lap after the leader was passed by the last lapped car.
Instead of lining up on the grid when a race is suspended, the cars would proceed slowly to the pit lane. The first driver who arrived in the pit lane would continue to the exit, which would be closed, with the rest of the drivers lining up behind.
Any drivers whose team personnel or equipment was still on the grid after the fifteen-second signal would have to start from the pit lane. If this was not obeyed, a ten second stop-and-go penalty would be given.
Penalties were no longer caused by the replacement of a whole power unit, instead for the power unit's separate components. If a driver could not take a full grid place penalty, the remainder of the penalty would be counted as a time penalty during the race depending on the number of grid spaces still included in the penalty.
After the British Grand Prix, the rule had been changed to exclude time penalties served during races, with the maximum penalty for changing engines being to start at the back of the grid.
A new ten-second penalty was added to the five-second penalty, served in the same manner of in the middle of a scheduled pit stop.
Drivers who were released from their pit stops in an unsafe manner would receive a ten second stop-and-go penalty. If drivers were believed by the stewards to know of this and tried to drive their car regardless, they would receive further penalties.
The qualifying procedure was made more clear so to match the starting grids' different sizes. Seven drivers were eliminated after each of the first two qualifying sessions if there were twenty-four cars. Six drivers fell into the knockout zones of Q1 and Q2 if there were twenty-two cars, and so on if there were less.
Helmet designs in-season were banned so that fans could easily recognise the drivers.
If a driver did not compete for two seasons in a row, they would lose the rights of their racing number.
The Mercedes-Benz SLS safety car was taken over by a Mercedes-AMG GT.
Former Caterham driver Giedo van der Garde challenged with Ericsson and Nasr's deals in the Victorian Supreme Court a week before the Australian Grand Prix, saying that Sauber broke a promise to have him drive for them after he signed a contract in July 2014. On the Wednesday preceding the race, Van der Garde won the case, although he dismissed it on Saturday so to get the goal of finding a different permanent solution later in the season.
Alonso was hospitalised after having a crash in the first Barcelona test, and had elected to miss the Australian Grand Prix on doctors' advice, with Magnussen taking his place.