Hannah G., Caelynn, Nicole, Onyeka, Katie, Jane, and Sydney all competed on Colton Underwood's season of The Bachelor earlier this year.
Annaliese appeared on Arie Luyendyk Jr.'s edition of The Bachelor in 2018, Wills fought for Becca Kufrin's heart on The Bachelorette's fourteenth season, and Derek tried to win over JoJo Fletcher on Season 12 of The Bachelorette.
Derek is only about a year removed from his breakup with Bachelor in Paradise alum Taylor Nolan. The pair got engaged on the spin off's fourth season in 2017 but subsequently split in June 2018.
While it was filmed in earlier this spring, Kevin was just shown being eliminated by Hannah Brown on last night's episode of The Bachelorette.
Chris initially found fame way back on Emily Maynard's season of The Bachelorette.
After appearing on multiple subsequent spinoffs and never finding lasting love, Chris famously announced his "retirement" from The Bachelor franchise in 2015. However, Chris has apparently had a change of heart.
Tayshia and Demi were on Colton's season, Bibiana appeared on Arie's edition, Blake and Clay both competed on Becca's season, and Cam and John Paul Jones were recently ousted from Hannah B.'s edition of The Bachelorette.
ABC will announce additional Bachelor in Paradise cast members in the future, however these 19 cast members arrived at the resort in Mexico on Day 1 as Season 6's original cast members when filming began earlier this month.
Reality Steve spoiler blogger Steve Carbone pretty much nailed the Day 1 lineup in his reporting except he did not anticipate Sydney would be one of the original cast members.
Carbone also claimed one other man from Hannah B.'s currently-airing season of The Bachelorette would appear on the first day, although it remains to be confirmed since ABC would wait until after his The Bachelorette elimination to announce him. Click here to read the spoiler.
It will be interesting to see how Kristina, Danielle and Dean interact considering they were involved in a love triangle the last time they all appeared on the Paradise spinoff together.
Carbone reported over 30 people will show up at the resort in Mexico for the new Bachelor in Paradise season.
As mentioned above, click here if you are interested to read the spoilers on which two guys from Hannah B.'s season -- who are still competing for her heart -- are expected to show up on Bachelor in Paradise this summer.