The figures, released by the Las Vegas Convention and Visitors Authority (LVCVA), contributed to a record 41.1 million visitors overall in 2014, 1.4 million more visitors than the previous high of 39.7 million set in 2012.
Rossi Ralenkotter, president/CEO of the LVCVA, said the latest results point to continued recovery for Las Vegas tourism.
"Breaking the 40 million visitor mark has been a goal of ours, and reaching beyond that to more than 41 million is a testament to the hard work of our resort partners and everyone who works in the industry," he said.
"Tourism drives our local economy, and the growth in recent years is a positive sign for both the industry and our community. With more than $9 billion (£6bn) in recent and planned developments, we are poised to continue that growth and march toward our next goal of 45 million visitors in the coming years," he added.
Average citywide occupancy also grew 2.4 percentage points to 86.8% for 2014 – 22 points higher than the national average of 64.1% - and the average daily room rate increased by $6 (£4) to nearly $117 (£78).
Las Vegas tourism generates more than $45bn (£30bn) in economic impact for the local economy and supports 376,000 local jobs.