The Army v Navy game is an annual fixture that marks the end of the college American football season and is the final game of the season's Commander-in-Chief's Trophy series.
It is one of the great American sporting rivalries, representing the fierce competition between two branches of the US Armed Forces.
In a photo taken from outside Trump's suite in Northwest Stadium in Landover, Maryland, on Saturday, Mr Penny could be seen talking with Trump and Vance.
Speaking about Mr Penny's acquittal earlier this week, Vance said this week on X that Mr Penny was "a good guy, and New York's mob district attorney tried to ruin his life for having a backbone".
The incoming vice-president added that it was "a scandal" that New York District Attorney Alvin Bragg ever prosecuted the case.
Mr Neely's death, and the subsequent trial, became a flashpoint, with some accusing Mr Neely of being a vigilante, while others defended him, arguing he was looking out for other passengers' safety.
Mr Penny's lawyer, Steven Raiser, said in a statement that his client was honoured by the invitation to Saturday's game.
"He's not viewing it as a political statement. He's viewing it as just basically an honour," Mr Raiser told Reuters news agency.
"If it were a president in office who was a Democrat, who invited him to the Army-Navy game as a way to show support to the military and for his country, he would have gladly accepted that as well."
Also at the game was Pete Hegseth, Trump's pick for defence secretary, and Florida Governor Ron DeSantis, who has recently been rumoured to be in the running to replace Hegseth, should Trump withdraw the offer.
Hegseth's nomination has come under intense scrutiny amid questions about his qualifications and personal conduct.
Trump's nominee to be director of national intelligence, Tulsi Gabbard, his nominee to be director of the FBI, Kash Patel, Republican House of Representatives Speaker Mike Johnson and Trump ally Elon Musk were also at the game.
