The mark of 271,865, set during the 2013-14 Ashes, was passed early on day four when a crowd of 30,500 were in the venue.
Saturday attracted 83,073 fans, a record for day three at a Boxing Day Test.
Thursday's baking heat meant Boxing Day fell short of breaking the all-time crowd for a day of Test cricket - 91,092 in 2013 - but 87,242 fans still attended.
Cooler conditions on Friday meant 85,147 fans - a record for day two of a Boxing Day Test.
The record MCG Test crowd is 350,534 in the 1936-37 Ashes series, when Don Bradman was king and Tests could be player over six days, or sometimes longer if they were timeless.
The previous record for an Australia-India Boxing Day Test was 194,481 in 2014, wicketkeeping great MS Dhoni's red-ball farewell.
"I've not seen anything like it at a cricket match," Melbourne Cricket Club boss Stuart Fox said on Sunday.
"I think that just the spirit in the stadium ... all of our staff on day one just said how happy the crowd were."
It continues a monster year for the MCG following three sold-out Taylor Swift concerts of her iconic 'The Eras Tour in February', and the AFL season averaging 60,000 per-match.
"I thought Taylor Swift was big, but this has been something else," Fox said.
"The year prior (2023), we had 4.4 million (people) through the gates.
"We might fall marginally short of that.
"But I think with Taylor Swift coming in, a fantastic AFL season, then this Boxing Day Test, it's (2024) going to be hard to beat, I can assure you.
"But plenty of great content ahead (with the women's Ashes Test next year)."
PREVIOUS BEST BOXING DAY TEST ATTENDANCES (ALL ASHES):
* 2013: 271,865
* 2017: 261,335
* 1974: 250,250.
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