Michael Salmon, 30, used his position as freelance producer of a show, "Cosy", at Cardiff's Millennium Centre, to obtain grants.
Some grants came from the Arts Council of Wales and Arts Unlimited, set up to fund projects with disabled performers.
Salmon, from Grangetown, Cardiff, admitted five counts of fraud.
The court heard that he used £9,000 to fund his own lifestyle, mainly on trips to London.
But most of the money he defrauded was lost by his own mismanagement of several theatrical projects.
One grant of £30,000 was obtained by falsifying a bank statement.
The deception took place between May 2015 and February 2016.
Jailing Salmon, Judge Paul Lewis QC said he had lied to theatrical directors who had gone to him for help in raising grants for their productions.
He said: "This was public money intended for good causes which never reached them.
"There was substantial financial mismanagement with money being transferred from one project to another when it shouldn't have been."
An independent theatre producer who fraudulently claimed £65,000 in grants has been jailed for 18 months at Cardiff Crown Court.