Parker's dismissal comes after just four games into the new season.
The Cherries started the campaign on a bright note, beating Aston Villa 2-0 on the opening weekend but have since been served a stark reality of what it takes to dine with the big boys.
Saturday's record-equalling 9-0 defeat at the hands of Liverpool followed a 3-0 defeat to Arsenal and 4-0 loss against champions Manchester City.
Bournemouth have now conceded 16 goals in their four games, more than the number of goals Chelsea's 2004/2005 title winning side shipped that season(15).
Parker was appointed Bournemouth manager in June last year and guided them to Premier League promotion at the first time of asking.
A statement on Bournemouth's website on Tuesday read: "AFC Bournemouth can announce that the club has parted company with head coach Scott Parker.
"Gary O'Neil will take interim charge of the team, and will be assisted by Shaun Cooper and Tommy Elphick."
Bournemouth co-owner Maxim Demin said on Parker's departure: "I would like to place on record my gratitude to Scott and his team for their efforts during their time with us. Our promotion back to the Premier League last season under his tenure will always be remembered as one of the most successful seasons in our history.
"However, in order for us to keep progressing as a team and a club as a whole, it is unconditional that we are aligned in our strategy to run the club sustainably. We must also show belief in and respect for one another. That is the approach that has brought this club so much success in recent history, and one that we will not veer from now.
"Our search for a new head coach will begin immediately."
