Gillespie, who is currently the Yorkshire coach, believes reviving the competition, which was scrapped in 2014 after six seasons, could lift the global profile of local T20 teams.
"There are World Twenty20s but they are at least two years apart. While there may be T20 matches in bilateral series, there are not usually too many of them and let's face it, they're a money-grab," Gillespie was quoted as saying by Cricket Australia's website on Tuesday.
"Perhaps you don't even need to have T20 matches between countries outside the World T20. Perhaps that would be the way to promote the Champions League and give it the status and profile it deserves."
"As was the case before it was halted, you would stage it in a three-week block in a single country. It's a fantastic opportunity for the game and all involved should look closely at bringing it back."
The 41-year-old said he knows it is not on the agenda at the moment but he hopes the administrators will look back and ponder over it.
"It doesn't seem to be on the agenda at the moment, yet I think it would be a fantastic idea to revive it. I'm convinced it could be structured so players, administrators and media supported it," he said.
"It's a fantastic concept: bring in the best teams from the various T20 competitions around the world and establish which of them is best. What is not to like about that?" he asked.