Jayson McDonald, aged 37, from Acton, west London, was found hiding under a bed in Amsterdam, the Netherlands.
Paul Monk, 54, from Romford, east London, was later captured at his luxury villa in Alicante, Spain.
They were arrested as part of Operation Captura, an international drive to catch suspects who have fled the UK.
In March, both men were included on a list of the operation's top ten most wanted suspects.
They are wanted by the Metropolitan Police on suspicion of drug offences and are currently in custody awaiting extradition proceedings.
Mr Monk was overseeing workmen laying a marble patio around his Spanish swimming pool when armed police swooped.
An imitation firearm with silencer and 125,000 euros were recovered from the address.
On Wednesday morning, Mr McDonald was apprehended as part of a separate joint investigation with the Dutch National Police.
He is wanted on suspicion of conspiracies to import and supply heroin and cocaine, and is believed to be a member of a Europe-wide organised crime network responsible for the importation of Class A drugs into the UK.
Mr Monk is wanted on suspicion of conspiracy to supply cocaine and conspiracy to supply cannabis.
A total of 68 out of 86 fugitives have now been caught under Operation Captura.
The operation was launched in 2006 and involves officers from the National Crime Agency, Crimestoppers and Spanish authorities.
In March, its most wanted list also included ex-soldier Shane Walford who was jailed in 2010 for the manslaughter of an off-duty fireman while on leave from the army.
Mohammed Jahangir Alam, 32, who was sentenced to 14 years in his absence in March 2010 for rape and sexual assault, was also featured.
Two suspected drug traffickers, who featured on the UK's most wanted list of fugitives, have been captured within 24 hours of each other.