Billy Corgan has struggled with depression for much of his life, including bouts of self-injury, obsessive-compulsive disorder, and suicidal thoughts. Corgan attributes this to the abuse he endured as a child, as well as his personal anxieties and issues. While he believes he is far more stable now, he still occasionally battles depression and has become an advocate for support networks.
His mother Martha died in December 1996. The song "For Martha", from Adore, was written in her memory. In the early 2000s, Corgan would name his label Martha's Music after her as well. A picture of Martha as a little girl sitting on a fake moon at Riverview Park is featured on the flipside of the Siamese Dream booklet.
Corgan is an avid sports fan. A childhood fan of the Cubs, he later commented on that team for WXRT DJ Lin Brehmer. He has appeared at Cubs games many times, occasionally throwing the ceremonial first pitch or singing "Take Me Out to the Ballgame". He was a devoted fan of the Chicago Bulls and Chicago Blackhawks in the 1990s, and became personal friends with Dennis Rodman and Chris Chelios. He is a lifelong fan of professional wrestling and self-described "wrestlemaniac," and appeared in an ECW pro wrestling wielding an acoustic guitar as a weapon. In 2008, the Pumpkins song "Doomsday Clock" was used by Ring of Honor for promotional videos. On April 26, 2010, Corgan appeared live on the SIRIUS Satellite Radio program "Right After Wrestling" with Arda Ocal to discuss his love for pro wrestling and the importance of unique theme songs for characters. On August 26, 2010, Corgan took part in a professional wrestling storyline with wrestlers from the Mexican promotion Asistencia Asesoría y Administración, during a concert for MTV World Stage. As far as other entertainment, Corgan once commented that all he watches on TV are "sports and Three Stooges." In March 2008, he was spotted in the crowd at the final day of the cricket test match between New Zealand and England in Wellington.
He incorporates elements of Catholicism and Buddhism into his spiritual philosophy, even though he has not publicly aligned himself with any one faith. On September 9, 2009, Billy launched Everything From Here to There, an interfaith website that is devoted to "Mind-Body-Soul" integration. He mentions praying each morning and night to be able to see through Christ's eyes and feel with his heart. On his drive to create art and music, he said, "God is just out my back door, yet I choose not to visit. I would rather sit alone and scheme on how to be remembered, on what more that I can do here to cement the evidence that I once walked these roads with you. It is a futile exercise. I know it is, and yet I persist."
While Corgan typically avoids discussing US politics, he said after the 2008 presidential election, "I'm very proud of my country right now for doing the right thing." In 2009, he posted a transcript of a webcast by political activist Lyndon LaRouche to the official Smashing Pumpkins forum. On March 10, 2009, Billy Corgan testified in front of congress on behalf of the musicFIRST Coalition. Corgan spoke in favor of H.R. 848, the Performance Rights Act, which gives musicians and artists their share of compensation when their music is played on music radio stations.
In 1993, he married his longtime on-again, off-again girlfriend, museum book restorer and artist Chris Fabian. They were married at a small ceremony at his house in Wrigleyville. Rumors circulated that Corgan and Love rekindled their romance during the Pumpkins' 1994 Lollapalooza tour, after Cobain's death. Corgan and Fabian separated sometime in 1995, and divorced in 1997. Corgan refused to discuss the subject in interviews, saying "There is not and will not be any public record on my marriage - that's one thing I have to draw lines around." He nevertheless described the circumstances of his marriage in his online Confessions, in 2005.
In late 1995, he started dating photographer Yelena Yemchuk, who had contributed to several Smashing Pumpkins videos and album art. The 2000 Smashing Pumpkins hit "Stand Inside Your Love" was written about her. He continued to date Yemchuk until around 2004. According to Corgan, his breakup with her contributed to the themes of his 2005 solo release, The Future Embrace. In 2008, Corgan said, "I've had a bad marriage and seven bad girlfriends in a row", a perspective he attributes to his dedication to music.
In early 2006, Corgan moved in with Courtney Love and her daughter, Frances Bean Cobain. According to Love, he had his own wing in her new Hollywood Hills mansion. Two years later, Love criticized Corgan publicly over the latter's alleged refusal to attend Frances' sweet 16 birthday party. In 2009, he was spotted on several occasions with LA weather forecaster, Jackie Johnson, fueling rumors that the two were dating. Things have been rocky between him and Courtney Love the past few years, but the level of tension has increased. In March 2010, Corgan stated in an interview in reference about Love "I have no interest in supporting her in any way, shape or form. You can't throw enough things down the abyss with a person like that" and said he parted ways with her. Shortly after, when Hole's Nobody's Daughter was released, Corgan unleashed on his Twitter a set of anger-filled tweets against her in reference to including two songs he wrote, "Samantha" and "How Dirty Girls Get Clean," that ended up on the new album without his permission. Love then wrote an apology to him on her Facebook, but things heated up. Billy took to his Twitter again in six tweets, attacking her again. Courtney responded to Corgan's tweets saying "All i am is nice about you so if you wanna be mean be mean i dont feel anything. i have too much to feel dear." 
In late 2009, Corgan was reportedly involved romantically with singer and actress Jessica Simpson.  , although the couple had reportedly split up.  According to the photographer Kristen Burns, Corgan and Simpson were working together on the song during the recording sessions to Pumpkins' concept album project Teargarden by Kaleidyscope.  In January 2010, the couple has been pictured by Burns in the studio with the producer Kerry Brown who linked to the pictures on his Twitter account. Simpson herself posted a series of messages regarding the common session, saying: "I am blessed. Going over a song with Billy and the boxer."  and "He braids my prayers."