On June 23, 2008, Hardy was drafted to the SmackDown brand as a part of the 2008 WWE draft.
Hardy made his debut for the brand on the July 4 episode of SmackDown, defeating John Morrison.
Hardy participated in the WWE Championship Scramble match at Unforgiven and also challenged for the championship at No Mercy and Cyber Sunday, but failed to win each time.
He was originally scheduled to be in the WWE Championship match at Survivor Series, but, in storyline, was found unconscious in his hotel stairwell, allowing the returning Edge to replace him in the match and win the title.
At Armageddon, Hardy defeated Edge and Triple H in a triple threat match to capture the WWE Championship, his first world championship.

In January 2009, Hardy's next storyline led to his involvement in scripted accidents, including a hit-and-run automobile accident and an accident involving his ring entrance pyrotechnics.
At the 2009 Royal Rumble, Hardy lost the WWE Championship to Edge after Hardy's brother, Matt, interfered and turned on Hardy, hitting him with a steel chair.
The buildup to this feud involved Matt implying that he was responsible for all of Hardy's accidents over the past few months, and at WrestleMania XXV, Matt defeated Hardy in an Extreme Rules match and in a stretcher match on the April 10 episode of SmackDown.
In a rematch at Backlash, however, Hardy defeated Matt in an "I Quit" match to end the feud.

On the following episode of SmackDown, Hardy won a fatal four-way elimination match to become the number one contender for Edge's World Heavyweight Championship at Judgment Day, but lost to Edge after Matt interfered and attacked him.
Hardy then defeated Edge in a non-title match on the following SmackDown to earn the right to choose the stipulation for their rematch at Extreme Rules and chose a ladder match.
At Extreme Rules, Hardy won the match to become World Heavyweight Champion for the first time.
Immediately after the match, CM Punk cashed in his Money in the Bank briefcase and defeated Hardy to win the championship.
He received his rematch against Punk in a triple threat match also involving Edge on the June 15 episode of Raw, but failed to win.
Hardy got another rematch at The Bash, and won the match via disqualification after Punk kicked the ref in the back while feigning an eye injury with Punk still retaining the title.
At Night of Champions, however, Hardy defeated Punk to win the championship for the second time.
He made his first successful title defense five days later on SmackDown by defeating John Morrison.
After the match, he was attacked by Punk, who invoked his rematch for the following week, where Hardy retained the championship after interference from Matt Hardy, who was the special guest enforcer.
Punk again attacked Hardy post-match, resulting in Teddy Long announcing a Tables, Ladders, and Chairs match between the two for the World Heavyweight Championship at SummerSlam.
At SummerSlam, Hardy lost the title back to Punk.
On the August 28 episode of SmackDown, Hardy lost to Punk in a steel cage rematch for the World Heavyweight Championship, resulting in Hardy leaving WWE, in storyline, per the pre-match stipulation.
This storyline was put in place to allow Hardy to leave WWE to heal his injuries, including a neck injury.
Hardy also had two herniated discs in his lower back and was suffering from restless legs syndrome.
On June 23, 2008, Hardy was drafted to the SmackDown brand as a part of the 2008 WWE draft. Hardy made his debut for the brand on the July 4 episode of SmackDown, defeating John Morrison. Hardy participated in the WWE Championship Scramble match at Unforgiven and also challenged for the championship at No Mercy and Cyber Sunday, but failed to win each time. He was originally scheduled to be in the WWE Championship match at Survivor Series, but, in storyline, was found unconscious in his hotel stairwell, allowing the returning Edge to replace him in the match and win the title. At Armageddon, Hardy defeated Edge and Triple H in a triple threat match to capture the WWE Championship, his first world championship.
In January 2009, Hardy's next storyline led to his involvement in scripted accidents, including a hit-and-run automobile accident and an accident involving his ring entrance pyrotechnics. At the 2009 Royal Rumble, Hardy lost the WWE Championship to Edge after Hardy's brother, Matt, interfered and turned on Hardy, hitting him with a steel chair. The buildup to this feud involved Matt implying that he was responsible for all of Hardy's accidents over the past few months, and at WrestleMania XXV, Matt defeated Hardy in an Extreme Rules match and in a stretcher match on the April 10 episode of SmackDown. In a rematch at Backlash, however, Hardy defeated Matt in an "I Quit" match to end the feud.
On the following episode of SmackDown, Hardy won a fatal four-way elimination match to become the number one contender for Edge's World Heavyweight Championship at Judgment Day, but lost to Edge after Matt interfered and attacked him. Hardy then defeated Edge in a non-title match on the following SmackDown to earn the right to choose the stipulation for their rematch at Extreme Rules and chose a ladder match. At Extreme Rules, Hardy won the match to become World Heavyweight Champion for the first time. Immediately after the match, CM Punk cashed in his Money in the Bank briefcase and defeated Hardy to win the championship. He received his rematch against Punk in a triple threat match also involving Edge on the June 15 episode of Raw, but failed to win. Hardy got another rematch at The Bash, and won the match via disqualification after Punk kicked the ref in the back while feigning an eye injury with Punk still retaining the title. At Night of Champions, however, Hardy defeated Punk to win the championship for the second time. He made his first successful title defense five days later on SmackDown by defeating John Morrison. After the match, he was attacked by Punk, who invoked his rematch for the following week, where Hardy retained the championship after interference from Matt Hardy, who was the special guest enforcer. Punk again attacked Hardy post-match, resulting in Teddy Long announcing a Tables, Ladders, and Chairs match between the two for the World Heavyweight Championship at SummerSlam. At SummerSlam, Hardy lost the title back to Punk. On the August 28 episode of SmackDown, Hardy lost to Punk in a steel cage rematch for the World Heavyweight Championship, resulting in Hardy leaving WWE, in storyline, per the pre-match stipulation. This storyline was put in place to allow Hardy to leave WWE to heal his injuries, including a neck injury. Hardy also had two herniated discs in his lower back and was suffering from restless legs syndrome.
Jeff Hardy