The company has been at top for 38 consecutive months, DisplaySearch added.
LG Display Inc. came second with selling 1.34 billion U.S. dollar worth of units, followed by AU Optronics Corp. of Taiwan with sales of 1.19 billion U.S. dollars, DisplaySearch said.
The data by DisplaySearch showed around 37 million LCD units were sold in June, up 13 percent from a year earlier.
Samsung Electronics attributed its good performance to its focus on premium products differentiated by wider panels and higher definition.
"We should be able to expand our lead, with our eight-generation production lines meeting stable demand and expectations for an increase of sales in the second half on seasonal factors," Samsung Electronics said.