The operator launched the casino app in New Jersey last month and it is now also available in the Keystone State.
Casino players could previously only play through DraftKings' sportsbook but the brand is now expanding its focus within the vertical.
Suppliers such as IGT will provide games on the app, while Pennsylvania players will soon have access to the DraftKings Live Dealer Studio.
A dominant force within daily fantasy sports and later sports betting, DraftKings has since expanded into virtuals, casino and live casino.
The launch in Pennsylvania marks another opportunity to generate revenue online, with only limited states offering online gaming in the US and retail properties still suffering from revenue declines due the coronavirus pandemic.
New Jersey this week reported a 66% fall in overall gaming revenue year-on-year, although online revenue shot up within the state.