The 24-year-old captained Adelaide Strikers to glory in this year's Big Bash League and was the competition's fourth highest run-scorer while he impressed with an innings of 96 in Australia's consolation win over England in the recent one-day series.
Head, who has 34 one-day international and 10 Twenty20 caps, could boost his Test prospects as he will feature in all three formats for Worcestershire.
Worcestershire, promoted last season to division one of the country championship, said they would be looking for "another leading overseas player" in Head's likely absence for Australia's five ODIs and one T20 in England midway through the campaign.
"We are delighted to have signed Travis," said Worcestershire vice-chairman Tim Curtis.
"Travis will start the season with us in April and will be with us right through to and including T20 finals day on September 15. He will miss two championship games in June when Australia have an ODI series and a T20I against England over here.
"But he is ambitious to play Test cricket and Cricket Australia have encouraged him and other young players to play cricket this summer."
First Published: February 9, 2018, 6:37 PM IST