The Taunton club continue to acquire cover for Will Sutherland, whose proposed stint was cancelled after a back injury suffered during the Sheffield Shield
Australia international Riley Meredith has joined Somerset on a multi-format deal for much of the rest of the county summer.
The 27-year-old's primary assignment will come in the T20 Blast title defence which begins next week.
Meredith is available for the entire group stage and at least the quarter-finals, which are scheduled in the first week of September.
He will remain at Taunton across that period, freeing him up to play a "managed" number of County Championship matches and in the One-Day Cup campaign.
Will Sutherland's overseas deal was cut short in March (Getty Images)
Somerset have two red-ball games starting at the end of June and August against Nottinghamshire, Warwickshire home and away, and Durham.
Will Sutherland was originally signed up through to the end of the Blast group stage but withdrew with a back problem suffered in the Sheffield Shield.
The Tasmania seamer has represented Australia in white-ball internationals, all coming in 2021, and enjoyed IPL spells at Punjab Kings and Mumbai Indians. His T20 career reads 114 wickets in 91 matches.
His first-class career is modest, with 82 wickets at 34.79 in 29 outings. Nine of those came as Tasmania reached a first Shield final since 2017/18.
Related: County cricket ins and outs 2024: Signings, transfers, squad updates
Meredith has played six white-ball internationals for Australia in 2021 (Getty Images)
Set for his first county stint, Meredith was scheduled to play for London Spirit in The Hundred during 2022 but injury saw him replaced by countryman Nathan Ellis.
"I'm looking forward to the challenge of playing in English conditions and I can't wait to get started," he said.
"Somerset are one of the biggest names in the English domestic game and I'm excited to be able to play a part in their journey this year.
"Somerset are the current Vitality Blast champions and I’ll be doing everything I can to help them retain the title."
Join The Cricketer's brand new Whatsapp channel for the latest breaking news, comment and features - click here to become a member
Welcome to www.thecricketer.com - the online home of the world’s oldest cricket magazine. Breaking news, interviews, opinion and cricket goodness from every corner of our beautiful sport, from village green to national arena.