Comic book fans are celebrating their favorite superheroes on National Superhero Day. Whether it's someone from the DC side or one of the superheroes at Marvel, everyone has their own personal favorites. It's the perfect opportunity to recognize these iconic characters, and thousands of Marvel and DC fans alike are talking about some of the most popular superheroes on Twitter. (Amazing art above by Mike S. Miller).

"It's #NationalSuperheroDay, so I present you my favorite," one fan tweeted, including several images of Robert Downey Jr. as Tony Stark, aka Iron Man. A fan of the Man of Steel said, "Happy #NationalSuperheroDay! He's the first, the best, and will always be my inspiration no matter what. If you know me, you know how much Superman means to me."

Another Twitter user with a display name reading Strongest Avenger tweeted: "Happy #NationalSuperheroDay to Captain Marvel and Captain Marvel only." Celebrating the occasion by wearing a superhero on his feet, another fan posted, "Rocking my #Batman socks for #NationalSuperheroDay. Which superhero are you rocking?"

"Happy #NationalSuperheroDay to the greatest Superhero. Chadwick Boseman, forever," reads another tweet, accompanied by photos of the late actor visiting young Black Panther fans in the hospital.

"It's #NationalSuperHeroDay," says someone else. "I had a Wonder Woman swimsuit I wore all day and all night to the point that my mom had to cut into pieces because it had been worn through and was see through. She was my inspiration and idol."

One tweet reads: "Today's #NationalSuperheroDay - whoever your favorite is, make sure to let your fandom show today! I know I probably wouldn't be alive today if not for #GreenLantern Hal Jordan."

And a Ryan Reynolds fan tweeted: "#NationalSuperheroDay well Deadpool is no Superhero but @VancityReynolds is! Thank you Ryan for everything you do. Thank you for making me happy and laugh when I'm sad with your hilarious movies and interviews you're a true superhero."

Marvel Studios is celebrating with a promo for Black Widow, their next superhero movie due to arrive this summer. Starring Scarlett Johansson reprising her role from the MCU, the movie will be released in theaters and on Disney+ with Premiere Access on July 9. Black Widow will also officially mark the start of the Phase Four movies on the big screen.

"It's #NationalSuperHeroDay and Natasha Romanoff will always be our hero," the studio said.

For their part, DC also announced the date for DC FanDome this year. In a tweet posted by the company, it was revealed that the "epic global event" will return on Oct. 16, 2021. Last year's event brought about tons of big DC-related news, so it will definitely be worth checking out the festivities again this fall.

Meanwhile, for many others, recognizing National Superhero Day is about paying tribute to some of the real-life superheroes doing their best to help others each and every day. Whether we're talking about characters from comic book lore or someone in real life that you know, it's a good day to pay tribute to whoever leaves you feeling inspired. You can find a wide variety of different answers from people naming their favorite superheroes under the hashtag #NationalSuperheroDay on Twitter.