While newly-promoted neighbours Birmingham have made six signings since the end of last season, Villa have been distinctly quiet.
Villa are in need of recruits having lost captain Gareth Barry and back-up goalkeeper Stuart Taylor both to Manchester City, while Martin Laursen has retired.
Lerner thinks the world of O'Neill, who has been at the helm since 2006, and believes he is the right man to continue the club's progression.
The American billionaire is delighted with O'Neill's work to date at Villa Park and has now promised he will have cash to spend this summer in order to strengthen his squad.
"Martin's achievements have been superb," stated Lerner in the Daily Express. "We have improved steadily and we have qualified for Europe two seasons in a row.
"He has a reputation as a very good manager, with good success, and that will play a part when playing are thinking of coming to Aston Villa.
"The funds will be in place for him."