Stephen Colbert has been a part of Aaron Walsh’s nightly routine for years. On Thursday, that routine was a little different. With tickets in hand for Mr. Colbert’s “Late Show” finale, Mr. Walsh was outside the Ed Sullivan Theater in Manhattan eagerly awaiting the send-off after a nearly 15-hour drive.

“It is sinking in we are in New York City and here to see the show,” said Mr. Walsh, 32, who had traveled from Lansing, Mich.

Hundreds of people were lining the sidewalk outside the theater for the final taping of “The Late Show With Stephen Colbert,” whose cancellation CBS announced last year. Supporters and fans traveled from around the country and the world hoping to be in the audience when Mr. Colbert bids his final farewell and the show’s lights go dark.

Among them were Nancy Salanger and Karen Palazzi, two sisters who wore matching “The Last Show With Stephen Colbert” shirts and held poster boards supporting a presidential run and declaring “You’re Still Our Americone Dream,” a nod to Mr. Colbert’s Ben and Jerry’s ice cream flavor.

After months of unsuccessfully trying to get tickets through an online waiting list, they decided to try their luck with standby tickets outside the theater on Thursday, said Ms. Palazzi, 70, who had traveled from Massachusetts. No such luck.

“We wanted to be in the room where it happened, even though we’re not going to be in the room where it happened,” Ms. Salanger, 68, who is from Syracuse, N.Y., said with a laugh. “We’re going to be on the street where it happened.”

The street outside the theater was full of Colbert frenzy, as supporters turned up in the rain, some without tickets, just to be part of the farewell. The crowd erupted into spontaneous chants of “Stephen” and burst into cheers as people made their way inside the theater. National and international media outlets swarmed the sidewalk, and the Naked Cowboy strolled by and serenaded the line.

Next to the line of fans was the pope. Or a pope. Brenda Ellis, 62, was there with a pointy white and gold pope hat and bright red robes, in a nod to Mr. Colbert’s dream of having Pope Leo XIV as a guest on his show. Many in line took pictures with Ms. Ellis and said they hoped the pope would appear on the show via video call.

Mr. Colbert is a late night host who can do it all, from humorous spins on the news to poignant conversations with guests, Ms. Ellis said.

“Everyone respects him, and it shows,” said Ms. Ellis, 62. “CBS was cowardly.”

When CBS’s corporate parent, Paramount, made the call to cancel “Colbert,” it had recently agreed to pay President Trump $16 million to settle a lawsuit over the editing of an interview on the CBS News program “60 Minutes.” The president’s lawsuit had been seen as a potential hurdle to a multibillion-dollar sale of Paramount to the Hollywood studio Skydance, which requires the Trump administration’s approval.

Fans have been rallying to Mr. Colbert’s corner ever since. After getting a ticket online just a few days ago, Marko Sirka hopped on a nine-hour flight from Finland, arriving in the city late Wednesday night.

For Mr. Sirka, “The Late Show” has been part of his breakfast routine for 11 years. It runs at 7 a.m. on YouTube in Finland. “It brings the joy to the day,” said Mr. Sirka, who said he was in his 40s. He wanted to thank Mr. Colbert for “all the good times.”

Samantha Cooperman and Kelly Lauberth were sharing an umbrella after becoming fast friends while waiting outside the theater. Both women had snagged tickets but had traveled from very different places: Ms. Cooperman from New York City and Ms. Lauberth from the Kansas City area.

Ms. Cooperman wondered what would be next for the Ed Sullivan Theater, which she described as an institution that is part of the “character of the city.”

“I’m sad that come tomorrow, the theater will be closed, and we don’t know what it will become,” she added.

As the audience members filtered in, fans without tickets lingered outside, hoping Mr. Colbert might make an appearance.

Earlier in the day, Janet Baker of Franklin, N.J., caught a glimpse of Mr. Colbert’s arrival, leaping from his car like “Superman,” she said. Ms. Baker, who had arrived around 7 a.m., toting drinks and turkey sandwiches in a bucket with Mr. Colbert’s face, did not have a ticket but had seen the show in person 15 times, she said.

She brandished a giant handmade fan with pictures of Mr. Colbert on it along with quotes from the show and questions she would want to ask him. It was important that she support his final act, she said.

“Stephen’s going to go on to some amazing and wonderful things,” Ms. Baker said. “And I’m going to support him.”