South Africa fast bowler Dale Steyn will play for Glamorgan in the first half of their T20 Blast campaign.
The 32-year-old is set to play in Glamorgan's first seven T20 games once he has finished his spell for Indian Premier League side Gujarat Lions.
"I'll do all I can to give the team the best possible start," said Steyn.
Australian paceman Shaun Tait, another of the world's fastest bowlers, will play for the Welsh county in the second half of their 14-game T20 campaign.
Steyn has played in 42 T20 internationals for South Africa as well as 82 Tests and 112 one-day internationals, boasting the best bowling strike rate in Test cricket among bowlers who have bowled a minimum of 10,000 deliveries.
"We've had to remain patient in our search for overseas talent this season, but we're delighted to have got this deal over the line" said Glamorgan chief executive Hugh Morris.
|Dale Steyn Factfile|
|Born: June 27, 1983 in Phalaborwa, Transvaal Province, South Africa||Previous clubs: Northerns, Titans, Essex, Warwickshire, Royal Challengers Bangalore, Deccan Chargers, Cape Cobras, Sunrisers Hyderabad, Gujarat Lions|
|Test record: South Africa (82 matches, 406 wickets at a 22.53 average)||Honours: ICC 2008 Test Cricketer of the Year Award, Wisden Cricketer of the Year 2013, Wisden Leading Cricketer in the World in 2013 & 2014|
|T20 international record: (42 matches, 58 wickets at a 17.39 average)||ICC Ranking: 4 (best Number one between 2008 & 2014)|
|Nicknames: Steyn Remover, Steyn Gun, Phalaborwa Express||Did you know?: Steyn played a cameo role as himself in 2014 Hollywood film Blended|
Glamorgan, who have not won any of their opening five County Championship Division Two games, start their T20 campaign against Surrey at The Oval on Thursday, 26 May.
Steyn has played just one game for the Lions and the timing of his Glamorgan debut will depend on how far they progress in the IPL.
Gujarat finish their group matches on Saturday but are strongly placed to reach the knock-out stages, meaning Steyn would miss the opening Glamorgan game at Surrey.
Steyn played in two games at the 2016 T20 World Cup and is likely to be required for South Africa's Test series against Australia in September.
The national selectors rested him from a one-day series in the West Indies in June, hoping he would stay fresh for five-day cricket.
But Steyn, who is also due for a brief spell with Jamaica Tallawahs in this season's Caribbean Premier League, said "The timing of this opportunity with Glamorgan is ideal."
Glamorgan missed out on a T20 quarter-final place last season on the final night of the group stages, while in 2014 they lost by just one run in a quarter-final at Lancashire.