Kaplinsky joined the BBC in 2002 and gained fame beyond its news programming with her appearance in the first series of 'Strictly Come Dancing'.
She won the series with dance partner Brendan Cole, with whom she was alleged to have had an affair that broke up her relationship with long-term boyfriend Michael Barnard.
Five is planning to relaunch its news programming with Kaplinsky, who takes over as the main anchor from Kirsty Young. Young left the channel at the end of August and has moved on to BBC Radio's 'Desert Island Discs' and BBC One's 'Crimewatch'.
Jay Hunt, Five's director of programmes, called Kaplinsky "one of the most talented broadcasters on British television" and said she had demonstrated her popularity with viewers from 'The Six O'Clock News' to 'Children in Need'.
Kaplinsky will be reunited with Hunt and another former BBC colleague, David Kermode, the Five News editor.
She said: "After five incredibly rewarding years at the BBC, I found the chance to work with the team at Five too exciting to pass up. Five has changed the face of news before, and now they're going to do it again. I can't wait to be part of it."Five News is produced by Sky News, where Kaplinsky worked as a breakfast presenter before joining the BBC.
Kaplinsky is a former presenter of BBC One's 'Six O'Clock News' and its 'Breakfast' programme.
She joined the BBC from Sky News where she was a co-presenter on Sky News' 'Live at Five' following several months on that channel's early morning 'Sunrise' programme, having joined Sky News in 2000.
Prior to that, she was a presenter on 'London Tonight' and 'London Today' with Alastair Stewart.
She has also presented LWT's live Sunday morning current affairs programme, 'Seven Days'. She joined Meridian TV in 1997 where she moved to a main presenter's role on 'Meridian Tonight', the station's evening news programme.