The country music star was performing at the Route 91 Harvest festival on Oct. 1, 2017 when a shooter opened fire on the crowd from his room on the 32nd floor of the nearby Mandalay Bay hotel. Fifty-eight people were killed and nearly a thousand more were injured.
"Thinkin about our Route 91 family today. #vegasstrong," he wrote.
Others in the country music community joined Aldean by sharing their own heartfelt tributes.
Tim McGraw asked fans to observe a special moment of silence during the day.
"Please join my family and the entire country music community, at 10:05am PT / 1:05pm ET for a moment of silence to remember those lost and all who were affected one year ago today by the Route 91 tragedy. #CountryStrong #VegasStrong," he wrote.
The country duo Big & Rich tweeted, "One year. God Bless America & God Bless our Route 91 family. We won’t ever forget you."
Reba McEntire wrote, "Join me in pausing to remember those lost in the Route 91 tragedy a year ago today. My heart goes out to their families and friends."
The band Florida Georgia Line shared, "It’s a day none of us will ever forget. Today lets take a moment to remember those lost, hurt and affected."
Rocker Bret Michaels of Poison also marked the anniversary. The "Every Rose Has Its Thorn" singer tweeted a photo from a benefit concert he played for the shooting's victims and their family members. He also announced plans for another tribute show in the future.
"I am honoring them at a very special event in the desert next year," Michaels wrote.