Born in the northern New South Wales town, Tweed Heads, Holdsworth moved to Perth in Western Australia at an early age. In Perth, Holdsworth played all his junior rugby league for the North Beach Sea Eagles in the Western Australia Rugby League competition. He represented Western Australia at the Under 15 and Under 18 age groups.
Holdsworth spent two years in the Penrith Panthers' lower grades, before signing with the St George Illawarra Dragons for the 2004 season. He made his NRL debut while at the club and played 6 games in two seasons, before joining the Bulldogs, where he would play 70 games between 2006 and 2009.
Holdsworth then spent four seasons in the Super League, playing for the Salford City Reds and Hull FC. He represented the Exiles in 2012 and was described by English fullback Sam Tomkins as "very clever, powerful and an effective stand off".
- Forrest, Brad (6 March 2014). "DJ looks set for chance in halves". St George & Sutherland Shire Leader. http://www.theleader.com.au/story/2124900/dj-looks-set-for-chance-in-halves/. Retrieved 15 May 2015.
- Cronulla Sharks recruit Daniel Holdsworth has house robbed, AAP, dated 27 January 2014.