The deal will be the cornerstone of Birds Eye's multimillion-pound rebranding, which began last month.
The one-year deal, negotiated by Unilever sponsorship agency MGA Broadcasting, will see Birds Eye credits appear on the bulletins. Birds Eye will also get branding opportunities on www.five.tv/weather.
The brand replaces GlaxoSmithKline, which sponsored Five's weather bulletins from last October to January this year.
Sponsorship credits have been created by Birds Eye's ad agency Bartle Bogle Hegarty.