The suspects, ages 24 and 20, were arrested in South Yorkshire and Wiltshire, police said.
They are suspected of conspiring to commit offenses under the Computer Misuse Act of 1990.
"The arrests relate to our enquiries into a series of serious computer intrusions and online denial-of-service attacks recently suffered by a number of multinational companies, public institutions and government and law enforcement agencies in Great Britain and the United States," said Det. Mark Raymond of the Metropolitan Police Service's Central e-Crime Unit.
"We are working to detect and bring before the courts those responsible for these offences, to disrupt such groups, and to deter others thinking of participating in this type of criminal activity."He added.
The name "Kayla" was used in the suspected intrusions, police said in a statement.
Hacking group Lulz Security has claimed responsibility for attacks on targets such as Sony, the CIA and Britain's Serious Organised Crime Agency.
Today, Anonymous hacked the Texas Police Chiefs Association for #Antisec.
