The bank was fined nearly a half billion dollars last week for attempting to manipulate figures that were sent in to the British Banking Association's panel that sets the Libor or London inter-bank offered rate, and average of wholesale borrowing costs.
The average interest rates banks charge each other is the benchmark that helps set the rates for $350 trillion in consumer and commercial loans.
The British Broadcasting Corp. said Tuesday that Diamond would follow Chairman Marcus Agius out the door. Agius resigned Monday saying, "the buck stops here," concerning the bank's reputation.
But pressure from a raft of politicians and others continued to build over the scheme that regulators said was "pervasive" for four years.
Following Diamond's resignation, Chief Operating Officer Jerry del Missier, who was named to his post last month, also tendered his resignation.
The bank said last week that four top bank executives would "voluntarily" give up their bonus pay for 2011, including Diamond, who earned $23 million in total compensation in 2010.
Bonus pay is generally far larger than a bank executive's salary.
"I am deeply disappointed that the impression created by the events announced last week about what Barclays and its people stand for could not be further from the truth," Diamond said in a statement.
On Tuesday, Chancellor of the Exchequer George Osborne said Diamond's resignation was "the right decision for the country," where many people have been angry at banking executives since the economy began to sour in 2007.