1.Kate Hudson used this photo of her iconic Almost Famous character, Penny Lane, to remind everyone to vote:
2.Nick Jonas announced the news of the new Jonas Brothers Christmas song, "I Need You Christmas," by posting this photo of himself, Joe, and Kevin as kids during Christmas — as well as photos of themselves with their family during a recent Christmas.
3.In honor of Kendall Jenner's 25th birthday, Kim Kardashian shared this photo of the two of them in 1996:
4.Janet Jackson celebrated Nelly's 46th birthday by posting this photo of the two of them on the set of the music video for their 2006 single, "Call Me":
5.America Ferrera shared this cute photo of herself in her elementary school parade in the late '80s:
6.Demi Lovato remembered some of her favorite past Halloween costumes:
7.Martin Lawrence posted this clip from Martin in honor of the holiday:
8.Ronan Farrow shared this photo from when he dressed as an ol' timey newsboy for Halloween:
9.Naomi Campbell posted this clip from when she appeared on the Halloween episode of the Late Show with David Letterman in 1995:
10.Michelle Pfeiffer celebrated Halloween by looking back at some of the villains she has played throughout her career:
11.Natalie Portman shared this photo from when she dressed up in this costume that's open to interpretation:
12.Billy Ray Cyrus posted this photo of his kids Miley, Braison, Noah, Brandi and Trace Cyrus on Halloween night in the early '00s:
13.The Rock shared this photo of himself from 1976:
14.In honor of Willow Smith's 20th birthday, Will Smith shared this photo of her as a kid, as well as two current photos of her:
15.Jennifer Lopez posted this video clip of herself performing "My Love Don't Cost a Thing" on a TV show in 2001:
16.Lenny Kravitz shared this photo and story about learning to play the acoustic guitar in 1973:
17.And finally, Catherine Zeta-Jones paid tribute to Sean Connery, who died at age 90, by posting this behind-the-scenes photo of the two of them on the set of their 1999 film, Entrapment: