Woman critical after tram collision

A woman is in a critical condition in hospital with serious head injuries after being hit by a tram in Port Melbourne.

The woman aged in her 20s was walking her dog on Bridge Street about 8.30am on Tuesday when she stepped out in front of the tram.

"She saw the first tram but stepped out in front of a second tram travelling in the opposite direction," a police spokeswoman told AAP on Tuesday.

Her dog was also injured and was taken to a local vet.

The woman is in a critical but stable condition in the Alfred Hospital.