The 16-times grand slam champion proved too much for his Russian opponent, claiming a break of serve in each set to complete victory under the floodlights at the Khalifa Tennis Complex in central Doha.
Federer has improved throughout his five matches this week in Qatar, where he did not drop a set, and sealed victory in 79 minutes when Davydenko netted an attempted backhand pass to huge cheers from a capacity crowd.
It was a 67th career title for the 29-year-old, who hardly broke a sweat on another warm evening in the tiny Gulf emirate and celebrated victory with a brief smile amongst little celebration.
The Swiss served impeccably throughout, dropping just nine points on his serve as he demonstrated his solid form ahead of the season's first grand slam, the Australian Open, which begins in Melbourne on Jan. 17.
"I'm very happy to kick-off the season today this way I think I played an amazing match...it will give me a lot of confidence for the remainder of the season," Federer said in a courtside interview.
Davydenko, who brushed aside world number one Rafa Nadal in the previous round, struggled on the back foot during the first set as Federer moved him around the court at will with precision depth groundstrokes.
The Russian, ranked 22 in the world after slipping from a career high third, battled hard throughout, saving six break points in the first set and charging down every ball but was always under pressure on his own serve.
The second set was on serve until the ninth game when Federer broke Davydenko to love before serving out with ease to claim his third Qatar Open title.
