The top seed and world No 2 won 7-6 (7-1) 6-4, although he was forced to dig deep against his Italian opponent who held a brace of set points at 5-4 in the opening set.
In the end, there was just a single break of serve during the entire contest and it arrived in the final game of the match.
However, Federer had to survive a scare in the opening set when ??? at 4-5, 15-40, down ??? he saved back-to-back set points with a couple of aces.
Two points later Federer levelled matters at 5-5, producing another excellent serve which the Italian was unable to return.
In the 56-minute opening set, Federer???s eight aces to Seppi???s one proved decisive with the seven-time Wimbledon champion racing through the tie-break for the loss of a single point.
The second set followed a similar serve-dominated pattern, with Seppi missing another break point in the fifth game, while Federer failed with three of his own in the eighth.
But two games later the 17-time Grand Slam champion finally made the solitary break, clinching a hard fought triumph on his second match point.
The key to Federer???s success was another superb serving display, as he won 81 percent of first serve points compared to 65 percent by the world No 45 Seppi.
Federer will take a rest next week ahead of SW19, while Seppi heads to Nottingham for the final warm-up tournament on grass.