Badd Blood: In Your House was a professional wrestling pay-per-view (PPV) event produced by the World Wrestling Federation (WWF, now WWE). It was the 18th In Your House event, and inaugural Bad Blood and it took place on October 5, 1997, at the Kiel Center in St. Louis, Missouri. Seven matches were contested at the event.

The event was notable as it featured the promotion's first-ever Hell in a Cell match, which pitted The Undertaker against Shawn Michaels and saw the debut of Undertaker's storyline brother Kane, who interfered in that match by hitting the "Tombstone Piledriver" on the Undertaker, which allowed Michaels to win and become the number one contender for the WWF Championship against reigning champion Bret Hart at Survivor Series. The show would also mark the last time Vince McMahon was featured as the chief broadcaster of the commentating team for a pay-per-view event and started his career as an on-screen professional wrestler using a gimmick known by the ring name Mr. McMahon, based on his real-life persona. According to WWE, the Montreal Screwjob, which took place at Survivor Series 1997, is considered the beginning of the Attitude Era. Thus, Badd Blood: In Your House was the last WWF PPV of the New Generation Era.

This was one of the In Your House events which later became the title of an annual pay-per-view, replacing the method at the time of making new names for all events aside from the "Big Five" (Royal Rumble, WrestleMania, King of the Ring, SummerSlam, and Survivor Series). Unlike the other former In Your House events that also became PPVs over the following year after In Your House's discontinuation, Bad Blood (stylized with one "d" in "Bad") did not return until June 2003, becoming the annual June PPV; however, it was short-lived as the event was discontinued after the 2004 event, but was later revived in October 2024 on the 27th anniversary of this first event.

The show's theme song was the first theme song of former WWE star Steve Blackman.