The 93-year-old president unveiled a plaque at the newly named Robert Gabriel Mugabe International Airport, located 15 kilometers (nine miles) outside the centre of the capital.
The refurbishment of the airport has been condemned by opposition figures as a waste of money.
Activists from Mugabe’s ZANU-PF party had campaigned for it to be re-named, threatening to bar the transport minister from the president’s birthday celebrations in February unless their demands were met.
“Thank you most sincerely for the honour bestowed on me. It is indeed a great gesture,” Mugabe said at the ceremony at the airport, which first opened in 1957.
On Monday Mugabe sacked vice president Emmerson Mnangagwa, formerly one of his closest allies, in a dramatic move that appeared to open the way for his wife Grace to succeed him in office.
Mnangagwa has fled Zimbabwe and vowed to fight back against Mugabe, potentially triggering political instability in a country where the economy has collapsed over the last 20 years.
Mugabe has ruled Zimbabwe since its independence from Britain in 1980, and is accused of holding onto power through brutal repression of dissent, election rigging and corruption.
The president’s birthday has recently been declared a public holiday, while a $1-billion Robert Mugabe university is being planned, and many buildings and roads across the country are named after him.
The opposition MDC party has accused the president of spending money on wasteful projects. The country is grappling with an estimated unemployment rate of more than 90 percent.
The party said the re-naming of the airport “marks a new low in both the political and aviation history of Zimbabwe”.
“Robert Mugabe is fully determined to take the country down with him,” it said.
“The State has been virtually captured by Robert Mugabe and his wife.”
Mugabe, who is in increasingly frail health, is due to stand in elections again next year and has given no indication when he will retire.