Paxman will write regularly for FT Weekend, focussing on long-form writing, diaries and Lunch with the FT interviews.
FT editor Lionel Barber said: "I am delighted to welcome Jeremy into the FT family. He is a wonderful writer, an acerbic interviewer, and a charming luncheon companion. He will make a great addition to the long list of distinguished FT Weekend writers.
"This year we have invested significantly in the FT’s weekend edition with a new app and design, and we see growth in both print and digital subscriptions."
Paxman said he was flattered to be joining the FT as a contributing editor: "At last someone takes me seriously."
The BBC veteran will also be covering the 2015 general election results night for Channel 4, as announced in September.