Channel 4's late-night satirical show will return for a third series of six episodes in November.
Seann Walsh, Sara Pascoe, Josh Widdicombe and Paul Chowdrhy will join regular Rich Hall and 8 out of 10 Cats star Richardson on the stand-up team.
"Stand Up for the Week continues to be a showcase for some of the country's best comedians and we're thrilled that Jon Richardson will step up to host the new series," announced the broadcaster's commissioning editor Madeleine Knight in a statement.
Executive producer Andrew Beint of Open Mike Productions said: "Stand Up for the Week is an exciting fresh format which combines topical comedy with the atmosphere of a live stand-up gig.
"For the third series we are thrilled to be working once again with new host Jon Richardson and regular Rich Hall, and welcome newcomers Seann, Josh, Sara and Paul to the Stand Up for the Week team."
Stand Up for the Week will be filmed in front of a live audience at the new home of Clapham Grand in London.
Richardson's appointment marks the programme's third change in presenter. Patrick Kielty fronted the first series in April 2010.
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