Mitchell McClenaghan has agreed to play six T20 Blast matches for Middlesex this summer.
The bowler will arrive at Lord's in July as an overseas replacement for Kyle Abbott.
"Replacing one high-quality overseas fast-bowler with another was not easy but we have managed to do this with the signing of McClenaghan," managing director Angus Fraser told the club's official website.
"Mitchell's style, left-arm fast, gives him a point of difference and his skill has allowed him to take wickets wherever he has played."
The New Zealander added: "I am delighted to have signed for Middlesex for the NatWest T20 Blast. It's every player's dream to play at Lord's and I am delighted to have the opportunity to do so wearing a Middlesex shirt."
McClenaghan is currently playing in the Indian Premier League for the Mumbai Indians.
