How You Know Her: Berkley, 41, got us all excited as Saved by the Bell's resident nerd Jessie Spano and flaunted her moves in Showgirls. Her Saved by the Bell co-star Mario Lopez finished runner-up on the third season of Dancing. Partner: Val Chmerkovskiy

How You Know Him: The 24-year-old actor and singer is best known as Zac Efron's BFF Chad in the High School Musical films. He joined the online reboot of One Life to Live earlier this year and starred as Usnavi in Broadway's In the Heights in 2010. Partner: Karina Smirnoff

How You Know Him: Daughterty, 28, starred on Pretty Little Liars as Noel Kahn and currently recurs on Days of Our Lives as Brian. He also played Lt. Patrick Clarke on the seventh season of Army Wives. Partner: Peta Murgatroyd

How You Know Him: Known for his "Here's Your Sign" bit, the comedian launched the Blue Collar Comedy Tours in 2000 with Jeff Foxworthy. Engvall, 56, also headlined his own TBS sitcom The Bill Engvall Show. Partner: Emma Slater (new pro)

How You Know Her: The actress won four Emmys and a Golden Globe as Mary's sidekick (and scarf aficionado) Rhoda Morgenstern on The Mary Tyler Moore Show and its spin-off Rhoda. Harper, 74, was diagnosed with terminal brain cancer earlier this year, but recently announced that it's nearly in remission. Partner: Tristan MacManus

How You Know Him: The former wide receiver won a Super Bowl ring with the Tampa Bay Buccaneers and currently serves as an ESPN analyst. Johnson, 41, also played for the New York Jets, Dallas Cowboys and Carolina Panthers. Partner: Sharna Burgess

How You Know Her: The 31-year-old singer served as The Voice's social media correspondent for three seasons. Partner: Mark Ballas

How You Know Him: A former mechanical engineer, Nye, 57, hosted the popular '90s education series Bill Nye the Science Guy, which still airs in repeats on PBS. Partner: Tyne Stecklein (new pro)

How You Know Him: Osbourne, 27, shot to fame on his family's MTV reality show The Osbournes in 2002 and has since hosted the British fitness series Jack Osbourne: Adrenaline Junkie. In 2012, he was diagnosed with multiple sclerosis. His sister Kelly finished in third place on Season 9 of Dancing. Partner: Cheryl Burke

How You Know Her: Snooki, 25, GTL-ed it up for six seasons on Jersey Shore and currently stars on its spin-off Snooki & JWoww. Her Jersey Shore co-star Mike "The Situation" Sorrentino finished in ninth place on Season 11 of Dancing. Partner: Sasha Farber (new pro)

How You Know Her: Remini, 43, starred as Carrie Heffernan on The King of Queens for nine years and recurred as Stacey Carosi, opposite Elizabeth Berkley, on Saved by the Bell. She co-hosted The Talk's first season before getting fired — a dismissal that led to a feud between her and co-host Sharon Osbourne. (Osbourne's son, Jack, is also on Dancing this season.) Most recently, Remini made headlines for defecting from Scientology. Partner: Tony Dovolani

How You Know Her: The 27-year-old actress has played Mercedes on Glee since its inception, but has been demoted to recurring for its upcoming fifth season. Partner: Derek Hough