Brian Littrell

Littrell (left) with the Backstreet Boys in 2008

In 1997, Littrell was instrumental in bringing a lawsuit against the group's creator Lou Pearlman, claiming Pearlman had concealed information regarding the group's earnings. Bandmates AJ McLean, Richardson and Howie Dorough joined the lawsuit which eventually resulted in a number of settlements, details of which were not disclosed.[21][22] In 2000, he was among Teen People's 25 Hottest People Under 25, tying with Justin Timberlake of rival band *NSYNC.[23]

Littrell performing in 2005

Littrell longed to record Christian music, a genre he described as "pop positive".[24] In 2004, Littrell signed a solo deal with Reunion Records and released the solo album Welcome Home in 2005. Littrell co-wrote six of the songs on the album, which sold over 100,000 copies in the US and reached No. 74 on the Billboard 200 charts. On the Christian album charts, Welcome Home debuted at No. 3.[25] Four singles were released from the album – "In Christ Alone", "Wish", "Over My Head" and Welcome Home (You)", with the latter reaching No. 2 on the US Christian AC Charts. It was also No. 1 on Reach FM's Top 40 chart and on the US R&R Christian Inspirational charts for 3 weeks. In the summer of 2005, his solo single, "In Christ Alone", went to No. 1 on the Christian charts. Despite this change in his career, he remains a member of the Backstreet Boys.

Littrell won a Dove Award for Inspirational Recorded Song of the Year ("In Christ Alone") in 2006 along with songwriters Don Koch and Shawn Craig, and another in 2008 for "By His Wounds" with Glory Revealed. He also won Special Event Album of the Year in 2008 for Glory Revealed which was a compilation album with many other Christian artists; and in 2010, Special Event Album of the Year for Glory Revealed II.[26]

Littrell released two Christmas collections featuring his wife Leighanne and son Baylee, Brian Littrell's Family Christmas, released on December 6, 2010, and Christmas with the Littrells, released on December 6, 2011.

Littrell made appearances with the Backstreet Boys on Arthur, Sesame Street, and Sabrina the Teenage Witch, and he and bandmate McLean had cameos in Olive Juice, a film starring Littrell's wife Leighanne.[27] Littrell also performed with The Backstreet Boys on Saturday Night Live, in 1998 and 1999. In 2013, Littrell made an appearance in the film This Is the End with his bandmates.

During the band's hiatus, Littrell became committed to a number of other show business activities, most of them for charity. He has joined other celebrities in yearly NBA tours where he played basketball in every NBA city before a game, and has also played charity baseball games.

In June 1997, following the breakup of his relationship with girlfriend Samantha Stonebraker, Littrell met Leighanne Reena Wallace, an actress and model, on the "As Long as You Love Me" video set in which she was an extra.[28] Littrell stated in J-14 magazine about this relationship that he had been out of the dating game for a while and meeting Leighanne opened a whole new chapter for him. "I had just gotten out of a relationship with a high school sweetheart that didn't work out. I didn't really have my eyes or mind set on anybody. It was something that just happened. If I was looking, I wouldn't have been able to find her."[29] They dated for two years, and Littrell proposed on Christmas 1999; their engagement, along with the engagement of cousin and bandmate Kevin Richardson to Kristin Willits, was announced on MTV on February 15, 2000.[30] the couple married in September 2000 at Peachtree Christian Church in Atlanta.[31][32][33] On November 26, 2002, they had their son Baylee Thomas Wylee Littrell, who is now pursuing a similar path as his father's in the entertainment industry.

As of 2020, the family lives in Alpharetta, Georgia, near Atlanta, having been there since 2000 soon after Littrell and his wife got engaged.[34]

Littrell stated during a show in Georgia on the DNA World Tour that his wife lost her mother from a heart condition in June 2022 and was a matriarch to him and the family.[35][36][37]

Littrell was born with a congenital heart condition, making him susceptible to infections. He was diagnosed with a heart murmur at 6 weeks old. At 5 years old, he was hospitalized for two months due to a bacterial infection. Due to his hospitalization, Littrell was held back in school and had to repeat the first grade. In November 1997, doctors found his heart condition had caused his heart to enlarge considerably. Still, he underwent open-heart surgery on May 8, 1998 (which would be referenced by his scenes in the band's music video for "Show Me the Meaning of Being Lonely"). He later established the Brian Littrell Healthy Heart Club, a non-profit organization assisting children with heart conditions through medical, financial, and practical help.[38][39]

In October 2009, Littrell became infected with swine flu, causing the cancellation of the Backstreet Boys This Is Us promotional tour.[40]

In the 2015 documentary film, Littrell revealed his 2011 diagnosis of vocal tension dysphonia and dystonia. He continues to work with a therapist to help improve his condition.[41]

A devout Christian, Littrell has stated he believes it is the duty of Christians to be open about their faith, saying, "I think as Christians we need to join hands and mount up together and lift God up and talk about our faith publicly and talk about all of the things God has done for us in our life to touch other people."[42] Littrell, who has been born again since the age of 8,[43] has said that he attributes his success in life to God, and that his faith has always been "the utmost important thing" in his life.[44]

In 2019, a DNA heritage test revealed Littrell's ancestry to be 90.1% British Isles (20.7% English and 70.1% Irish/Scottish/Welsh), plus 7.1% Finnish and 2.1% Scandinavian.[45]