Conan opened his show on a somber note, calling the tragedy "terrible" and "numbing."
"I've been doing this job for more than 24 years and when I began in 1993, occasions like this were extremely rare, for me or any TV comedy host back then to come out and need to address a mass shooting spree was practically unheard of," Conan said. "But over the last decade, things have changed."
Conan explained that, in an effort to help shape his monologue, his head writer handed over a stack of papers with remarks the comedian had made after previous mass shootings at Sandy Hook and Orlando's Pulse Nightclub.
"And that struck me," Conan said. "How could there be a file of mass shooting remarks for a late-night host? When did that become normal? When did this become a ritual? And what does it say about us, that it has? Now I am not the most political of our comics, I never have been. But I will repeat what I said not long ago after Orlando, I don't think it should be so easy for one demented person to kill so many people so quickly. The sounds of those automatic weapons last night are grotesquely out of place in a civilized society."
"Tonight Show Starring Jimmy Fallon"
"In the face of tragedies and acts of terror, we need to remember that good still exists in this world," Fallon said before introducing Miley Cyrus and Adam Sandler's touching rendition of Dido's "No Freedom."
The CBS late-night host began by talking about the bravery of concertgoers, first responders and medical professionals in Las Vegas, recognizing their heroism before, during and after the massacre, all of which Corden said are "examples of true human nature than that shooter on the 32nd floor.”
Corden then called for action to be taken against gun violence.
"Last night was the biggest mass shooting in United States history. That's a record that's been set twice in just the two and a half years that I've been living in America," he said. "Here's another statistic: 11,660 people have died from gun violence in the last 275 days in this country. Now I come from a place where we don't have shootings at this frequency so it's hard for me to fathom. But it should be hard for everyone to fathom. Gun violence should not be a staple of American life. Some say it's too early to talk about gun control, for those victims last night it's far too late."
"I heard today a commentator on the news explaining there's no real way to prevent loan wolf mass shootings like this, and forgive me, as I'm just a foreigner here and some of you may feel I have no place to say this, but how does every other developed country do a better job at preventing these attacks?" he asked. "We can't be surprised that gun crime will always occur where there is such wide availability of guns. I saw a quote from Robert Kennedy that stayed with me today. He said that 'Tragedy is a tool for the living to gain wisdom, not a guide by which to live.' Now is the time for gaining that wisdom.”
"The Late Show with Stephen Colbert"
"This afternoon, the president called this 'an act of pure evil' and I think he's right," Colbert began at the start of his monologue. "So what, then, are we willing to do to combat pure evil? The answer can't be nothing. It can't."
"The bar is so low right now that Congress can be heroes by doing literally anything — universal background checks, or come up with a better answer, enforce Obama's executive order that denied mentally ill gun purchases, or a better answer, reinstate the assault weapons ban, or come up with a better answer," he continued. "Anything but nothing. Doing nothing is cowardice. Doing something will take courage. But you know what, it took courage for the people at that concert last night to help each other as bullets flew, it took courage for the first responders to rush in and do their jobs, it took courage for people in Las Vegas to simply go about their day today."
He then directed his monologue at Trump.
"Now President Trump, you've said you want to be a transformative president who doesn't care about the way things have always been done in Washington, D.C. This is your chance to prove it and I mean this sincerely. You do not owe the Republicans anything. You know the Republicans tried to stop you from being president, well screw 'em. You want to make America Great Again? Do something the last two presidents haven't been able to do. Pass any kind of common sense gun control legislation that the vast majority of Americans want."
The NBC late-night star also called out Congress to do something to combat gun violence.
"To Congress, I would just like to say, 'Are there no steps we can take as a nation to prevent gun violence?' or is this just how it is and how it's going to continue to be. Because when you say, which you always say, 'Now is not the time to talk about it,' what you really mean is, 'There is never a time to talk about it' and it would be so much more honest if you would just admit that your plan is to never talk about it and never take any action."
Meyers then led a round of applause for the heroism of first responders and all the heroes from Monday night.
"The Daily Show with Trevor Noah"
Like Corden, Noah also reminded viewers how many mass shootings there have been in America over the past two years, which is not the norm for the rest of the world.
"I've lived in the U.S. in New York for two years now, and in that time there have been 20 mass shootings. 20 mass shootings in the U.S. What's been particularly heartbreaking is -- other than the lives lost -- is how I feel like people are becoming more accustomed to this type of news. Every single time. I almost know how it's going to play out — we're shocked, we're sad, thoughts and prayers, and then almost on cue people are going to come out saying, 'Whatever you do, when speaking about the shootings, don't talk about guns.'"
Noah then showed multiple news clips, one of which was White House Press Secretary Sarah Huckabee Sanders saying that it's not the time or place for political debate, but a time for the country to unite.
"This is not the time to be talking about guns," Noah said. "Sometimes I wish I used this logic as a kid when I had done something wrong and my mom wanted to ground me. I should have just said: 'Is this the time, mom, that we politicize what's happening right now? This is not the time to talk about my lack of discipline. This is the time to unite as a family, to focus on the fact that I'm stuck in the kitchen window trying to sneak back in. Come on, mom. This is not the time.'"
"And if you say after a mass shooting is never the time, then you'll never have the conversation in America, because there is a mass shooting almost every single day. So when is the time?"
Noah finished with giving viewers an idea of how far the country is from any kind of a solution.
"Just to give you an idea of how far away America is from actual gun control – this week Congress is going to vote on deregulating gun silencers. Because I guess Congress is thinking gun violence is out of control. How can we make it quieter?"
In a 10-minute monologue, Kimmel slammed critics who say "there's nothing we can do about it," since gunman Stephan Paddock purchased the guns legally and passed background checks.
"There are a lot of things we can do about it. But we don't, which is interesting. Because when someone with a beard attacks us, we tap phones, we invoke travel bans, we build walls, we take every possible precaution to make sure it doesn't happen again," he said. "But when an American buys a gun and kills other Americans, then there's nothing we can do about that. And the Second Amendment, I guess, our forefathers wanted us to have AK-47s is the argument, I assume."
"They're weapons designed to kill large numbers of people in the shortest possible amount of time. And this guy, reportedly he had 10 of them in his room, apparently legally," Kimmel went on. "At least some of them were there legally. Why is that allowed? I don't know why our so-called leaders continue to allow this to happen. Or, better question, why do we continue to let them allow it to happen?"
"And you know what will happen, we'll pray for Las Vegas. Some of us will get motivated, some of us won't get motivated. The bills will be written, they'll be watered down, they'll fail," he added. "The NRA will smother it all with money and over time we'll get distracted, we'll move on to the next thing. And then it will happen again. And again."