The Northern Ireland champions have been given permission by UEFA to install additional seating at their Solitude home for the clash on July 17.
The Reds revealed at the weekend that all available tickets had been snapped up for the first leg of the second qualifying round tie against the Scottish champions.
However, fans of both sides look set to benefit from the news that Cliftonville have been given the green light to increase the capacity of their stadium which is currently around 2,500.
A statement on the club's website read: "Following communication with UEFA, Cliftonville Football Club has this morning received correspondence permitting the installation of additional seating at Solitude for the Champions League second qualifying round first leg tie with Celtic on Wednesday, July 17.
"This augmentation of capacity will result in an increased ticket allocation for both clubs and a further announcement on this matter will be made in due course."