[Walt Longmire]

Does anyone konw what the single game attendance record is for a KHSAA football finals?

 A glowing final attendance number for the Russell Athletic/KHSA Commonwealth Gridiron Bowl championship games would have been as good as any gift that KHSAA Commissioner Julian Tackett could have received on his 57th birthday. 
He got it. By the end of the final game on Sunday afternoon, the 2017 finals had blown past the previous all-time attendance high [color=var(--lc)]in recorded history, which goes back to 1984. A total of 52,796 fans ended up watching the six games at Kroger Field this year, the first time Lexington hosted the finals since 1976. [/color]

The previous overall attendance record was set in 2010, when 47,759 fans watched the finals at Houchens Industries/L.T. Smith Stadium in Bowling Green.







Single-game attendance records for the Class 3A and Class 5A championships were broken on Friday and Saturday, respectively. The Class A championship had its most heavily-attended game of the six-class era, which began in 2007.
The Class 6A game drew 9,791 fans, its highest attendance since 9,962 watched the 2009 finals in Bowling Green. Every game this weekend saw a marked improvement in its attendance from last season at WKU.

got that from Lex herald. Not sure if that’s the most accurate

The KHSAA page doesn't have the 2021 numbers.  But, going through the linescores, it looks like the most that they have listed is 26,430 for the 2003 4A final between Trinity and St. X.