Net profit for the three months to March 31 reached 953.2 billion won ($888 million). Sales were 10.66 trillion won, up 36.7 percent from the previous year.
Operating profit soared 90.1 percent from a year earlier to 839.9 billion won.
The company said in a statement that "strong sales of new models, improved brand image and efforts to enhance competitiveness" had led to the improved results.
It sold a total of 619,089 vehicles in January-March, up 30.4 percent from the previous year.
The United States remained the largest overseas market with 104,774 vehicles sold there in the first quarter. China, the world's largest and also fastest-growing market, was next with more than 95,000.
Kia Motors is South Korea's second largest automaker after its affiliate Hyundai Motor. Combined, they are the world's fifth largest automaker.