Brighton released an official statement confirming that they have decided to terminate Poyet's contract and plan to appoint an interim manager early this week.
Poyet learned of his dismissal while working as a pundit for BBC Sport on the Confederations Cup yesterday evening, with the Uruguayan sending a message to Brighton fans commending their patience with his approach during four years in charge.
He said: "I got an e-mail at 9.03 from the club and another one from my solicitors. I cannot go into details at this stage so it's just a matter of making the right decision.
"I been trying to establish what are my rights now, with talking to the press and informing them about things that until now I have not been able to do. My situation is now totally different. From what I read in the statement I am unemployed. My idea now is to appeal and get back to do the job I'd been doing.
"I would like to thank every single Brighton fan for being so patient with me and supportive. They were excellent and patient with me and I'm sure they are proud. I'm gonna try my best to be there but I'd like to thank them for all my support."
Poyet also revealed that he will appeal against the board's decision, with the 45-year-old awaiting advice from his legal team before proceeding.