Murgatroyd is returning to the series after taking a season off to give birth to her first child with fiance Maksim, son Shai Aleksander. Johnson is also making a comeback after a hiatus following her marriage to Robert Herjavec, whom she was paired with for Season 20.
Motsepe is the only other pro dancer in the cast who didn't compete on Season 23.
Murgatroyd wasn't present in the studio but joined the GMA broadcast from Los Angeles to reveal she will be partnered with Viall, The Bachelor's current star.
"I am super excited," Murgatroyd noted.
"This is going to keep me in shape, I think, a little better right? Rather than going home and just eating chips all day on the couch," Ross told Michael Strahan and Robin Roberts on GMA of his participation. "I figured I'd do this to keep me in shape and get outside my comfort zone and hopefully represent the MLB, be the first baseball player to stay a little long [in the competition]."
Morris has "a little bit" of confidence going into the new DWTS season having been on Glee and danced on tour with Beyonce, but she said ballroom is "very different" from the style of dance she's used to, so she's "a little iffy."
Roberts pointed out that Murgatroyd, Maksim and Val have won four of the last six mirrorball trophies on Dancing with the Stars. Val insisted there is no family tension, adding, "Hopefully we can get another one."
But Val has his work cut out for him, as Kordei is currently on tour in Asia with Fifth Harmony and writing another album.
"I told [Val] the schedule and he freaked out a little bit," the singer confessed, "but we're going to make it work... [We'll fly] back and forth, so it's going to be crazy. I better eat my vegetables."
"It's not just a tour," Val clarified as to why he freaked out about the news. "It's a tour literally on the other side of the world."
Bolton was apparently surprised by doctors to be cleared to dance on the show after a life-threatening bull-riding accident last year.
"I was super pumped when they first told me [I could dance]. But after I said, 'yes,' I thought, 'Man, I kind of took on Mount Everest!' So I might be more nervous that climbing on a bull right now, but I'm excited," Bolton admitted.
Kerrigan's kids are "excited" for their mom because they "watch the show together... They think it's going to be a lot of fun," she said.
While Girardi, who goes by her stage name Erika Jayne, said she's going to give the show all she's got -- with a lot of "sass -- Charo yelled about how she loves Dancing with the Stars and this is her "moment."
David Ross will be partnered with Lindsay Arnold, a former So You Think You Can Dance contestant. Arnold will be taking the stage as a pro dancer for the fifth time on DWTS. She finished Season 21 in third place with Alek Skarlatos, Season 22 in fourth place with Wanya Morris, and Season 23 in third place with Calvin Johnson Jr.
Nancy Kerrigan will be matched up with Artem Chigvintsev, who served as a member of theDancing with the StarsTroupe before appearing as a first-time pro in Season 19, during which he finished in sixth place. He hasn't been able to place higher than that ever since.
Simone Biles will be paired with Sasha Farber, who first appeared as a pro on Season 17 of DWTS with Nicole "Snooki" Polizzi. He later served as Derek Hough's alternate in Season 20 when he got hurt mid-competition. Farber served as a pro in Season 22 and finished seventh again with Kim Fields. And then last season, he placed fifth with Terra Jole.
Chris Kattan will take the dance floor with Witney Carson, a former So You Think You Can Dance contestant and DWTS Troupe member who made her debut as a pro on Season 18. Carson won Season 19 with Alfonso Ribeiro and placed fourth in Season 21 with Carlos PenaVega. She finished in eighth and then tenth place on Season 22 and 23, respectively.
Nick Viall will be dancing with Peta Murgatroyd. She will be gracing the stage again for her tenth season. She made her debut as a pro on the series' 13th season and was the first pairing voted out, however, she went on to win DWTS' 14th season with celebrity partner Donald Driver. She placed fourth on Season 18 with James Maslow and eventually won Season 22 with Nyle DiMarco.
Charo will be taking the stage with Keo Motsepe. He will be appearing on the reality dancing competition for his fifth season. In Season 22, he finished in sixth place with Jodie Sweetin after having difficulty making it past Week 3 on the show.