The 30-year-old Kichenok and Pavic, seeded seventh, beat Belgium's Joran Vliegen and China's Xu Yifan 6-4 6-7(9) 6-3.
Former doubles world number one Pavic, also 30, adds the Wimbledon mixed doubles titles to five other Grand Slam doubles titles, three in men's and two in mixed.
Earlier on Thursday, wildcard Svitolina was beaten 6-3 6-3 by Czech Marketa Vondrousova in the women's semi-finals.