Djokovic will try for his tour-leading 10th title of the year after eighth- seeded Czech Tomas Berdych withdrew from their bout after dropping the first set, 7-5.
Berdych, who defeated two-time defending champion Roger Federer in the quarters on Friday, broke the Serbian's serve to go up 4-3 and had a chance to serve for the set. But Djokovic broke back in the 10th game when Berdych doubled faulted and then won the next two games before the latter retired, citing a right shoulder injury.
The victory moved Djokovic to an incredible 57-1 this year, including 33-0 on hard courts. The 24-year-old is seeking his sixth Masters title of the season. Djokovic, the 2008 and 2009 Cincy runner-up, beat Mardy Fish in last week's Masters finale in Montreal.
Earlier Saturday, Murray cooled off Fish, posting a 6-3, 7-6 (10-8) triumph over the sizzling American.
Fish finally had his serve broken after 30 straight holds as Murray grabbed a 3-1 lead in the first set. The fourth-seeded Murray fought off a break point to stretch his advantage to 4-1 and saved two more in the ninth game en route to taking the opening set.
There were six breaks of serve during the second set.
Murray held serve to even it at 5-5, then had a triple break opportunity in the next game. The seventh-seeded Fish managed to escape, then wasted two set points as Murray rallied to force a tiebreak.
The World No. 4 Murray overcame another set point before converting his third match point to reach his third final in 2011. He won his second Queen's Club title in June and lost to Djokovic at the Australian Open.
Murray, the 2008 Cincinnati champ, is 3-6 lifetime against Djokovic.
Fish had advanced to three straight finals, winning in Atlanta before losing to Latvia's Ernests Gulbis in Los Angeles and Montreal a week ago.
This week's winner will collect $496,000.