The win was Serena’s second Wimbledon title within five hours, with victory earlier in the women’s singles at the All England Club.
The pair won 6-3 6-4 against Timea Babos and Yaroslava Shvedova to claim their sixth Wimbledon doubles title and 14th doubles Grand Slam.
The win is their first in Grand Slam doubles since Wimbledon 2012.
The Williams sisters tally of 14 titles means now only Martina Navratilova and Pam Schriver have more as a pair.
Earlier, the reigning Olympic champions beat Timea Babos of Hungary and Kazakhstan’s Yaroslava Shvedova 6-3 6-4 on Centre Court.
This came hours after Serena claimed a record-equalling 22nd Grand Slam singles title by defeating Germany’s Angelique Kerber 7-5 6-3.
Serena has now won both the Wimbledon singles and doubles (with Venus) in the same year on four occasions.
For Venus it was a consolation after she lost to Kerber in Thursday’s singles semi-finals.
The German had denied her a first Grand Slam singles final since losing to Serena at Wimbledon in 2009.
The sisters, who paired up again this year after a two-year absence, have won 14 Grand Slam doubles titles together.
This had moved them level with American Gigi Fernandez and Belarussian Natasha Zvereva in second place on the all-time list.
They still have some way to go, however, to match the 20 of Navratilova and fellow American Shriver.