Hayward joined the board at TNK-BP after a corporate reshuffling last October moved Bob Dudley to the top position of BP following the Deepwater Horizon accident in the Gulf of Mexico. Hayward had led BP during the response to one of the worst offshore oil spills in the history of the industry.
The board at TNK-BP said it accepted Hayward's resignation after he informed the board he was stepping down to pursue other opportunities.
"We are immensely grateful to Tony Hayward for the outstanding contributions he has made to TNK-BP," TNK-BP Executive Chairman Mikhail Fridman said in a statement.
TNK-BP said it would replace Hayward "in due course."
Hayward is resigning from the board to head oil company Vallares in its takeover of Turkish energy company Genel Enerji, British newspaper The Daily Telegraph reported recently.
Hayward, the newspaper reported in April, is said to have complained he was a "sacrificial lamb" for BP in the wake of the gulf disaster.
"I am confident that his future endeavors will be successful and fulfilling," added Fridman.