Seth Rogen, Sarah Paulson and America Ferrera are among the stars urging voters to stay in queues at polling stations.
The contest between President Donald Trump and former vice president Joe Biden will see a close race in the state of Arizona, which went to Mr Trump in 2016.
The state represents 11 votes in the electoral college, which could be crucial in the race to 270 to win the election.
Rogen wrote on Twitter: “People of Arizona, PLEASE STAY IN LINE. If you’re in line, they must let you vote.”
Ugly Betty star Ferrera wrote: “Arizona!!! Stay in Line!!!! If you’re in line when polls close you have a right to vote!
“AZ can go blue! Every Vote will count!!! Stay in line! Please repost!”
Ratched star Paulson wrote: “Calling all voters in line in Arizona: DO NOT LEAVE. YOU HAVE THE RIGHT TO VOTE. TELL YOUR FRIENDS AND NEIGHBORS.”
Black-ish actress Tracee Ellis Ross also urged voters to be patient and wait, writing: “#Arizona voters: Stay in line! If you are in line at your polling location by 7pm then you have the right to #vote.”
Amber Tamblyn also urged voters to stay in the queue as polling stations close, writing: “IF YOU ARE IN LINE IN ARIZONA, STAY THERE AND CAST YOUR VOTE!
“DO NOT LEAVE THE LINE. LET ME REPEAT: DO. NOT. LEAVE. THE. LINE.”
Ben Stiller, Gabrielle Union and Dwyane Wade also used their social media platforms to urge fans and followers to wait in long queues to vote.