Feed and water if necessary and contain the bird.
Before we can deal with a stray pigeon it must be contained.
Because racing pigeons are domesticated birds they will respond better to being handled and nursed than most wild birds, so can easily be caught and contained.
A pet carrier is ideal but the pigeon will be quite safe if contained in a suitably large cardboard box as long as it has sufficient holes to allow in air and light.
Once you have contained the pigeon, return to this webpage and follow the instructions on how to report a stray pigeon.