Taylor will play all three formats of the game from early April until July.
''I am delighted to be joining Sussex," Taylor said on the club's website.
''I've heard nothing but positive words about the setup at Hove and I look forward to contributing across all three forms.
Sussex were relegated to division two of the first-class championship last season. Taylor has been signed in the expectation that their current overseas player, Steve Magoffin, will be successful in his application to play as a local player, thus opening an overseas import spot.
''He is a brilliant all-round player with high skill in all formats of the game," Sussex coach Mark Davis said.
''To have secured one of the best batsmen in world cricket is testament to the ambition that we have at Sussex Cricket Limited."
Taylor is playing his 69th test, against Sri Lanka in Hamilton and averages 45.99 in tests.
- by David Leggat
