Earlier, 21-year-old Zverev beat Federer 7-5, 7-6 (7/5), denying the Swiss veteran won the 100th title and had the chance to avenge his defeat at the hands of Serbia earlier in the tournament.
"I am very happy I can play with a high level consistently week after week for the past six months," Djokovic said.
"I played very well in the group stage against Sascha (Zverev) but I don't think he was close to the best … This is the last match of the year for both of us so let the better players win."
Anderson came to the night contest knowing his service had to fire on all cylinders if he had a chance against Djokovic – one of the most back in match history.
But the South African giant landed only 48 percent of the first serve in the first set and Djokovic was cruel in punishing his opponent, breaking serve in the first game and repeating his performance before serving for the set.
Hitting the ball with mesmeric accuracy, Djokovic broke his opponent who faded at the start of the second set and once again in the fifth game to underline his total dominance.
Djokovic's number of services was even more phenomenal than he returned – he had never once lost four games in London and only had two break points.
When asked if he produced some of the best services in his career, he said: "Maybe. It's not too common to serve more aces than Kevin (six to four). That status helps confidence."
The new 14-time Grand Slam champion has only lost two matches since July because he lost time after elbow surgery and a poor start to the season.
Ball blunder for boys
Federer-Zverev's final match was overshadowed by an unusual incident, Zverev stopped the rally with Federer leading 4-3 in the second tie-break after a ball boy dropped the ball.
Zverev won points repeated with aces and poked 5-4 before Federer mysteriously netted with a simple forehand volley to hand over two German match points, the second he took his own service.
Annabel Croft's on-court interview told pro-Federer O2 groups to "be more respectful" after they showered him with ridicule, because Zverev had played according to the rules.
"Obviously the crowd didn't appreciate it, which I was a little annoyed at – not disappointed, but I was a little sad at last with the ridicule and reaction from the crowd," Zverev said.
"Maybe they don't know what really happened. That might be part of the reaction. But, you know, at the end of the day I said sorry to Roger on the internet. He said," Listen, you don't even apologize & # 39;
Federer described it as a "big call" but said Zverev could not be blamed.
Serving dominated the first set of high-class matches but Switzerland, the six-time champion in the Final, finally faltered in the 12th match.
The second seed rejoined and took the first blood in the second set, breaking serve in the third game with a crazed backhand that drew huge cheers from the partisan crowd.
However, a frustrated 20-time Grand Slam winner could not consolidate his position, losing the next match when Zverev equalized to 2-2.
In the end tie-break went serve until the 10th point, when Federer netted to give Zverev a mini-break – a profit he didn't spend.