Spain's 75-year-old king left hospital on October 1 after surgeons replaced his prosthetic left hip in the latest of a string of operations that have raised questions over his reign and fuelled speculation of a possible abdication.
Felipe presided over a military parade in Madrid, dressed in military uniform and accompanied by his wife Letizia as they briefly met with troops from the Royal Guard.
The parade lasted barely an hour and was a toned-down affair, in line with crisis-hit Spain's austerity regime.
The budget for the event has been cut by another 15 percent from last year and is now at 823,000 euros ($1.1 million) from 2.8 million euros in 2011.
In the absence of the king, who is also chief of the army, Prime Minister Mariano Rajoy represented the state's institutions, as the crown prince cannot replace the king at official functions.
Spain's national day commemorates the anniversary of Christopher Columbus's first arrival in the Americas on October 12, 1492.
Juan Carlos is widely respected for his role in guiding Spain's transition to democracy after the death of long-time dictator General Francisco Franco in 1975.
His image has suffered, however, in particular because of a corruption scandal implicating his youngest daughter Cristina, who was not present at the parade.