There were 708 cases of Britons arrested for drug offences overseas in 2013/14, up from 669 in 2012/13.
Of the cases, 173 were in Spain - a 68 per cent rise on the 2012/13 figure, with the FCO saying this may have been due to an increase in local authority action.
The second-largest number of drug arrests involving Britons last year was in America, with 102 cases. But this was a 29 per cent fall on the 2012/13 American total.
Overall, the FCO said drug arrests were low last year compared with previous years. There were 816 cases in 2011/12, 799 in 2010/11 and as many as 994 in 2009/10.
Despite the rise in drug arrests, the number of arrests for all offences involving British nationals abroad fell fractionally from 5,435 in 2012/13 to 5,418 in 2013/14.
The figures include Melissa Reid, one of the so-called Peru Two who were arrested for trying to smuggle £1.5 million worth of cocaine out of South America. The 20-year-old, from Lenzie, is currently in a Peruvian prison and has applied to be transferred to a facility in Scotland.