Amazon made a record net profit of $2.9bn (£2.2bn) during the third quarter to 30 September, up from $256m (£119m) during the same period in 2017.
Its operating profit increased from $347m (£270m) in 2017 to $3.7bn (£2.8bn).
Sales jumped 29% to $56.6bn (£44.1bn).
However, Amazon said it expected slower growth in sales between now and the end of the year. It forecasts net sales of between $66.5bn (£51bn) and $72.5bn (£56.5), up 10% to 20% on the fourth quarter of 2017.
Operating profit is expected to be between $2.1bn (£1.6bn) and $3.6bn (£2.8bn) in the fourth quarter, compared with $2.1bn (£1.6bn) during the same period last year.
Amazon recently announced plans to open a new office in Manchester and increase the capacity of its development centres in Scotland and Cambridge, which will provide additional capacity for over 1,000 new UK jobs.