She became the first Terrapin to get a triple-double since Marissa Coleman in 2006, which was the first in program history.
Tianna Hawkins, the ACC's leading scorer, scored 16 of her 27 points in the first half. Malina Howard and Tierney Pfirman each scored 11 points and Alicia DeVaughn had 10 for the Terrapins (6-2), who are the defending ACC champions.
Rahneeka Saunders scored 13 points and Kyana Jacobs had 10 for George Mason (4-4). Maryland, which leads the nation in rebounding margin, outrebounded the Patriots, 50-24.
The Terps shot 55.6 percent (35 of 53) from the field.
A free throw by Hawkins capped an 18-0 run by Maryland to open the game. George Mason did not manage any points until Janaa Pickard made a 3-pointer with 12:32 left in the first half.
Maryland used its considerable height advantage to continue to pull away. A pair of free throws by Hawkins in the closing seconds provided a 43-20 lead at the break. The Terps scored 15 points off 16 George Mason turnovers in the first half.
The second half was not much better for the Patriots as Hawkins scored 10 more points during a 17-3 run and Maryland increased the lead to 62-24 with 14 minutes remaining.
The Terps improved to 6-0 all-time against George Mason, which is located about 30-35 miles from Maryland's campus in Fairfax, Va.
Thomas was voted ACC Player of the Week the league announced Monday. This marks the 12th weekly honor for Thomas, who was named Rookie of the Week a record seven times in 2010-2011 and was named Player of the Week four times last season.
Next, the Terrapins will take on local opponent Towson (4-2) Tuesday at 7 p.m. at the Towson Center in Baltimore. Listen to Tuesday's matchup live online on UMTerps.com for a fee.
The Associated Press contributed to this report.