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Dr. John Robert "Johnny Mac" McGuire was a houseguest on Big Brother 17 (US).

John is best known for his loud and funny diary room confessionals. Despite being one of the most nominated HouseGuests in Big Brother history, he managed to get off the block four times by winning 3 PoVs and 1 BotB. His closest allies were Becky Burgess and Steve Moses, and his primary target was Vanessa Rousso, since he was the only person in the house to realize how much of a threat she was. In week 9, John and Steve were both nominated for eviction, and ultimately he was evicted unanimously. However, he managed to re-enter the game by winning the jury buyback competition. Upon returning, he re-aligned with Steve, and started working with his arch-nemesis Vanessa. He made the Austwins alliance as his new targets. Despite managing to lay low and improve his social game with the remaining houseguests, Vanessa evicted him on day 91, because of her suspicions of a possible final two deal he made with Steve. He placed 4th, and became the 8th member of the jury.

On finale night, John along with Jason and James was revealed to be the top three to win America's Favorite HouseGuest but lost to James.

He is secretly a super fan of the show, but kept that a secret to other HouseGuests to avoid being targeted. John also tied the male PoV record with 4 wins, which was shared by James Rhine and Shane Meaney until it got broken by Michael Bruner with 6. He became the first male in Big Brother history to save himself three times with the Power of Veto. Some of his fellow houseguests such as Steve, Liz Nolan and Vanessa suspected he was some sort of Twist due to his actions in the house.


Retrieved from

Age: 27
Hometown: Scranton, Pennsylvania
Current City: Jefferson Township, Pennsylvania
Occupation: Dentist
Three adjectives that describe you: Ninja-esque, klutz, and eccentric.
Favorite Activities: Playing guitars, lifting, running mud races, and occasionally getting drunk and dominating in a video game with my friends.
What do you think will be the most difficult part about living inside the Big Brother house: I don't know what that California heat is like, or earthquakes, so probably those two things.
Which past Big Brother cast member did you like most: This changes a lot as I get older. Right now, I'm going to avoid saying that I have ever liked anyone because my next sentence would confirm I'm a hypocrite. I hate watching nerdy know-it-alls like Ian, Nicole and Derrick because they let their knowledge of the game turn into hero worship and it's not what I watch the game for.
What are you afraid of: That the ’90s won't come back.
Finish this sentence: My life’s motto is… No God or kings. Only man. Yeah, I stole that one, but it's so true.
What would you take into the house and why: I would bring a Rubik’s cube to see who was smart enough to figure it out and get rid of them immediately. Also, maybe some shiny objects to distract the other ones, and a dragon.

John (aka Johnny Mac, the Rock Star Dentist) is unlike any other dentist. He is loud, obnoxious, and never seems to run out of energy. Recently, he’s taken up running Tough Mudder marathons and is excited to have a few showmances. Single and proud of it, if any girl wants more of a relationship, he has a sure-fire way of getting out of it—he'll start acting completely annoying and geeky, so they end up dumping him and no hearts are broken. He's a super-fan and wants to win so he can save his parents’ lake house and finally pay off his school loans.[2]

Player History - Big Brother 17[]

Competition History[]

Week 1 HOH Loss
POV Loss
Week 2 HOH Loss
Week 3 HOH Loss
Luxury Loss
Week 4 HOH Loss
POV Loss
Week 5 HOH Loss
BOTB Ineligible
POV Loss
Week 6 HOH Loss
POV Not Picked
Week 7 HOH Loss
POV Not Picked
HOH Loss
Week 8 HOH Loss
POV Loss
Week 9 HOH Loss
POV Loss
Week 10 Re-Entry/HOH Re-Entered
POV Not Picked
HOH Loss
POV Loss
Week 11 HOH Loss
POV Loss
Week 12 HOH/Luxury Loss
HOH Loss
POV Loss

Have/Have-Not History[]

Week 1 Have
Week 2 Have
Week 3 Have
Week 4 Have-Not
Week 5 Have
Week 6 Have
Week 7 Have
Week 8 Have-Not
Week 9 Have
Week 10 Have-Not
Week 11 Have/Have-Not Phase Over
Week 12

Voting History[]

Week Position Voted for With Majority?
1 BOTB Winner Jace Agolli Yes
2 Used POV on Self Da'Vonne Rogers Yes
3 Used POV on Self James Huling No
4 Nominated
5 Jason Roy Yes
6 Clay Honeycutt Yes
7 Shelli Poole Yes
POV Holder Jackie Ibarra Yes
8 Nominated
9 Nominated
10 Meg Maley Yes
11 Julia Nolan Yes
12 Used POV on Self Austin Matelson Yes
Finale Jury Member Steve Moses Yes

Post Big Brother[]

  • On November 7, 2017, John appeared on The Taran Show to talk about his music and dentistry.[3]
  • John attended Eric Stein's wedding on June 12, 2021.[4]
  • In Big Brother 25, John appeared in Week 12 to host the "Johnny Mac: Demented Dentist" HOH competition via pre-recorded messages.


  • John is the first player to be nominated every week the first four weeks.
  • John is the first houseguest on Big Brother 17 (US) to win the Power of Veto twice.
  • John is tied with James Zinkand, Victor Arroyo, Cliff Hogg III and Jag Bains for least amount of days spent evicted before re-entering the house, with all five players re-entering after being evicted earlier in the same day.
    • However, Jag was brought back immediately, James and Cliff were brought back before the live show ended, whereas John re-entered 3 minutes after the live show ended, and Victor re-entered 40 minutes after the live show ended.
  • John is tied with Spencer Clawson for most nominated male houseguest with 9 nominations.
    • Victoria Rafaeli holds the record for most nominations in a single season with 10.
  • John won the most Power of Veto competitions in Big Brother 17 with 4 wins.
  • John is the second houseguest, and first male, to save themself with the PoV three times. The first houseguest to accomplish this was Janelle Pierzina in Big Brother 7 (US).
  • He is the third houseguest to return to the house from jury and not win Head of Household or be evicted immediately upon returning. The others being Judd Daugherty, Nicole Franzel on Big Brother 16 (US) and Victor Arroyo.
    • However, he, along with Victor, are the only two to return right after they were evicted.


Big Brother 17 (US) Houseguests
BB17Small Steve
BB17Small Liz
BB17Small Vanessa
BB17Small John
BB17Small Austin
BB17Small Julia
BB17Small James
BB17Small Meg
BB17Small Becky
BB17Small Jackie
BB17Small Shelli
BB17Small Clay
BB17Small Jason
BB17Small Audrey
BB17Small Jeff
BB17Small Da'Vonne
BB17Small Jace