"Mr. & Mrs. Karp. Established 11/04/2018," Fishel, best known for playing Topanga Lawrence on Boy Meets World and the spin-off Girl Meets World, announced the exciting news on her Instagram account alongside an image from the couple's big day.
Karp also made the announcement via his official Instagram account.
"Today I married my soulmate," he wrote. "We were surrounded by family and friends and it was the best day of my life. I also ate 3 donuts after dinner. Unrelated. @daniellefishel, I love you so much and thank you for giving me this smile."
Fishel and Karp, who made their relationship Instagram official in June 2017, had announced that they were engaged in in March.
"I woke up today thinking it would be a normal day and it was anything but normal. I put on my Genghis Cohen t-shirt and went to see @jensenclan88 at work where I proceeded to screw up a very romantic marriage proposal by being too efficient (this is very on brand for me). The future Mr. and Mrs. Karp are now engaged and no one is more excited than I am," Fishel captioned an image of herself sporting a new diamond ring.
"We got engaged today. I don't have anything witty or funny to say to accompany this picture. She is just the greatest person in the world and to imagine someone I went to high school with was always my person, is remarkable. You never know," Karp captioned the same photo.
Earlier this month, Fishel opened up to Entertainment Tonight about wedding planning, revealing that she had found a dress to walk down the aisle in.
"My gosh, wedding planning is so much fun. I absolutely love it," she said. "Things are going along very well. We just wrapped up our invitations and they're stunning, calligraphy and vintage stamps."
"I do have a dress," she continued. "I've had a couple of fittings and yeah, I'm excited for people to see it. I kind of went a little bit of a unique route, but I like it."
This is the second marriage for Fishel, who previously married Tim Belusko in 2013. Following the finalization of their divorce in 2016, Fishel began dating Karp.