The four founders were co-headmasters: Godric Gryffindor, Helga Hufflepuff, Rowena Ravenclaw and Salazar Slytherin.
Armando Dippet.
Try Googling it next time. (found info in 5 seconds flat!)
Albus Percival Wulfric Brian Dumbledore
Dumbledore.
professor snape
Dumbledore, because he used to be a teacher (before Harry went to Hogwarts) but then got promoted to Headmaster.
Severus Snape is the headmaster of Hogwarts in Harry Potter and the Deathly Hallows.
Severus Snape was appointed headmaster after Lord Voldemort (indirectly) took over the Ministry of Magic.
Severus Snape
It is unknown. Minerva McGonagall retired and was not headmaster during the epilogue.
Dolores Umbridge
The only thing said about Hogwarts teachers is that Neville Longbottom is teaching the Herbology class. Nothing about who the Headmaster is, though. it may be McGonagall or Flitwick but that's just guessing
Dolores Umbridge.
professor snape
Dumbledore, because he used to be a teacher (before Harry went to Hogwarts) but then got promoted to Headmaster.
He was Professor of Transfiguration.
harry potter
severus snape takes over as headmaster once harry leaves school to search for the horcruxes.
Severus Snape is the headmaster of Hogwarts in Harry Potter and the Deathly Hallows.
Albus Dumbledore was the Headmaster of Hogwarts in Harry Potter and the Philosopher's Stone. Minerva McGonagall was the Deputy Headmistress.
Severus Snape was appointed headmaster after Lord Voldemort (indirectly) took over the Ministry of Magic.