When he was a toddler, his parents opened Fort Rock Family Camp. Along with his sister, Austin was homeschooled growing up, and often helped his parents out around the camp. As children/teens, Austin and his sister were not allowed to close their bedroom doors, except to change clothes.
On June 6, 2009, Country Music Television aired an episode of the reality TV show World's Strictest Parents featuring Austin's family, entitled "Forsyth Family". In the episode, two "unruly" teenagers, 15-year-old Arielle and 17-year-old Tyler, were sent to live with the Forsyth family for a week to help them "straighten up". In the episode, the two teenagers were expected to work alongside Austin and Meagan in a variety of tasks, including yardwork and household chores. They were also expected to go to White River Baptist Church with the family, an issue that Tyler argued strongly against on the grounds that he was Jewish. Both teens spoke of the Sunday School class they were forced to attend, stating that they were taught that dating lead to divorce.
On November 15, 2016, Austin announced that he was in a courtship with long-time friend Joy-Anna Duggar. The couple said that they had been friends for almost fifteen years, although Joy-Anna later said that she didn't remember him as a child. Austin took Joy-Anna out to a special spot at Pedestal Rocks in Ozark National Forest to ask her to court him, and she enthusiastically said yes. Their courtship proposal is featured on the Counting On episode "A Honeymoon & a Courtship".
On March 3, 2017, the couple announced that they were engaged. The couple got engaged on March 2, 2017, in the Ozark National Forest at Fort Rock. Austin took Joy-Anna, along with her younger sisters Johannah and Jennifer, horseback riding, before leading her to a cliffside where he proposed to her. He then took her to a clearing where he and his friend, Aaron Patton, had set up a table to eat a special meal that he had prepared for them. Joy-Anna said that she didn't expect a proposal at that moment because she didn't see any TV cameras there to film, but they were hiding in nearby trees and bushes to help make the moment more special. Their engagement is featured on the Counting On episode "Joy Gets Engaged".
On May 26, 2017, Austin married Joy-Anna Duggar at Cross Church in Rogers, Arkansas. The wedding had around 1,000 guests. The couple shared their first kiss at the altar. The wedding was officiated by Paul Caldwell. Austin's best man was his brother-in-law Bobby Ballinger. His groomsmen were his half-brother Brandon, his half-brother-in-law Nick, Joy's brother John-David, his grandfather Edwin Forsyth, and his friends Nathan Paine, Aaron Patton, Andrew Patton, Peter Query, Logan Smith, Josiah Stangl, and Jacob Wilson. The ring bearer is unknown. Joy's matron of honor was her sister Jill. Her bridesmaids were her sisters Jana, Jessa, Jinger, Johannah, and Jennifer, her sister-in-law Anna, Austin's sister Meagan, and her friends Kendra Caldwell, Carlin Bates, Sierra Dominguez, and Heidi Query. The flower girl was Austin's half-niece Allove. Their wedding was featured on the Counting On episodes "Joy's Wedding" and "Joy and Austin Tie the Knot".
The couple went to Switzerland for their honeymoon, starting in Geneva and later traveling to Interlaken and Zermatt. They chose Switzerland because they thought it was beautiful. Their honeymoon included skiing, navigating public transit, yodeling, eating fondue, and taking a class where they learned to make chocolate. Their honeymoon was featured on the Counting On episode "In Love in Switzerland". They then spent time in Israel, on a mission trip, before returning back to Arkansas.
On August 30, 2017, Austin and Joy-Anna announced that they were expecting their first child. On February 26, 2018, Austin and Joy-Anna announced that their son, Gideon Martyn, had been born at 3:39 p.m. on February 23, 2018. He weighed 10 pounds and 3 ounces, and was 22 inches long. This birth was featured on the Counting On episodes "Joy Gives Birth" and "A Birth-day and a Birthday".
On May 1, 2019, Austin and Joy-Anna announced that they were expecting what would have been their second child, due on November 9, 2019. On June 26, 2019, at their 20-week scan, they learned that they had suffered a miscarriage, and that their baby no longer had a heartbeat. Their child was a girl and they chose to name her Annabell Elise. Annabell means means "God has favored me", and Elise means "God satisfies". Joy delivered Annabell on July 1, 2019, and they later buried her on Austin's family's property at Fort Rock Family Camp, in a quiet, private part of the woods.
On March 18, 2020, Austin and Joy-Anna announced that they were expecting their second child, a daughter, due on August 19, 2020. On August 24, 2020, Joy-Anna and Austin announced that their daughter had been born at 2:12 p.m. on August 21, 2020. She weighed 8 pounds and 5 ounces, and was 19 ½ inches long. On August 27, 2020, they revealed her name to be Evelyn Mae. This birth was featured on Austin and Joy's YouTube channel.
During a 'Q&A' on Instagram, Joy revealed that both she and Austin had tested positive for Covid-19 while she was pregnant with Evelyn. They experienced body aches, fever, and lost their sense of smell and taste. Both had a quick recovery.
Austin often works at his family's business, Fort Rock Family Camp, in Combs, Arkansas.
Austin started doing construction work at a young age, and was given the ultimatum by his father that he had to buy and flip five houses before he could get married. He has continued to work flipping and selling houses since getting married. Austin is a Contractor and works building new homes.
Austin currently holds an EMT license, which expires on March 31, 2022. He used to work as an EMT.
Austin volunteers for MEDIC Corps, helping people around the world hit by natural disasters. He works alongside some of his in-laws and some of the Bates brothers.
Austin has been a volunteer firefighter at the Saint Paul Volunteer Fire Department, in St. Paul, Arkansas, since 2012.
Austin received his Private Pilot's license on April 4, 2020.