Ballard has signed a three-year deal at the Stadium of Light, with a club option of a further year, after making 31 Championship appearances on loan at Millwall last season.
The 22-year-old became the Black Cats second signing of the summer, after Leon Dajaku’s move from Union Berlin was made permanent due to a clause being triggered in his loan deal.
Making the step up to the Championship will be challenging, though, with many teams operating with bigger budgets and some having the advantage of Premier League parachute payments.
Here are all the signings that have been made by Championship clubs so far this summer:
Making the step up to the Championship will be challenging, though, with many teams operating with bigger budgets and some having the advantage of Premier League parachute payments.
5. Burnley
IN: Scott Twine (undisclosed, MK Dons), Luke McNally (undisclosed, Oxford), CJ Egan-Riley (free Manchester City), Taylor Harwood-Bellis (loan, Burnley) | OUT: Ben Mee (released), Aaron Lennon (released), Phil Bardsley (released), Dale Stephens (released), Erik Pieters (released), Joel Mumbongo (released), Richard Nartey (released), Anthony Glennon (Grimsby), Anthony Gomez Mancini (released), Nick Pope (Newcastle), Lukas Jensen (loan, Accrington Stanley), James Tarkowski (Everton) Photo: James Gill
6. Cardiff
IN: Ebou Adams (free, Forest Green), Jak Alnwick (free, St Mirren), Ollie Tanner (undisclosed, Lewes), Jamilu Collins (free, Paderborn), Callum O'Dowda (free, Bristol City), Vontae Daley-Campbell (free, Leicester), Mahlon Romeo (free, Millwall), Ryan Allsop (free, Derby), Andy Rinomhota (free, Reading) | OUT: Sam Bowen (Newport), Chanka Zimba (loan, Newport), Aden Flint (Stoke), Will Vaulks (Sheffield Wednesday), Marlon Pack (Portsmouth), Leandro Bacuna (released), Ciaron Brown (released), Josh Murphy (released), Alex Smithies (released), Isaac Vassell (released), James Connolly (Bristol Rovers) Photo: Dan Mullan
7. Coventry
IN: Kasey Palmer (undisclosed, Bristol City) | OUT Jordan Shipley (Shrewsbury), Jodi Jones (released), Josh Pask (released), Declan Drysdale (Newport) Photo: Marc Atkins
8. Huddersfield
IN: Will Boyle (free, Cheltenham) | OUT: Josh Austerfield (loan, Harrogate), Romoney Crichlow (loan, Bradford), Jaheim Headley (loan, Harrogate), Alex Vallejo (released), Reece Brown (Forest Green), Jamal Blackman (released), Fraizer Campbell (released), Naby Sarr (released), Carel Eiting (released) Photo: Gareth Copley