The discovery was made during an investigation in Port Glasgow on Friday, 4 December.
Police said the cultivation seized has a street value of somewhere between £600,000 and £1m.
A 16-year-old boy and a 40-year-old man have since been changed in connection with the drug find and are due to appear in court next week.
A police spokeswoman said: "At about midday on Friday, 4 December, 2020, officers, acting under warrant, searched a disused bingo hall on Brown Street, Port Glasgow, and discovered a cannabis cultivation with an estimated street value of a six-figure sum.
"A 40-year-old man and a 16-year-old male youth, have been charged and are expected to appear at Greenock Sheriff Court on Monday, 7 December, 2020."
Anyone with further information is encouraged to call police on 101.