The FIA said in a statement that it had tested a large number of devices over the past five years, and it had "become clear that the halo presents the best overall safety performance."
The decision to implement the halo comes less than a week after a transparent cockpit shield was tested for the first time on track at Silverstone last Friday in British Grand Prix practice. Ferrari's Sebastian Vettel said the transparent open canopy made him feel dizzy.
Cockpit protection has become a priority since the deaths of drivers who were hit by wheels and flying debris. In the 2014 Japanese Grand Prix, Jules Bianchi died in a crash with a recovery truck when his car slipped underneath, leaving his head vulnerable in the impact. In 2009, loose debris injured Felipe Massa during qualifying for the Hungarian Grand Prix.
FIA signaled a move to the halo two years ago. The device, which is fixed at three points - including a central pillar in front of the driver that supports a protective loop above his head - was extensively tested last season with a mixed response. The appearance of the device also drew criticism.
FIA said in January the net safety benefit had been established but a decision needed to be made about the aesthetics and whether such a system was right for Formula One.
FIA said in Wednesday's statement that certain features of the halo's design would be further enhanced with the support of the teams.
