Bible Society
https://www.biblesociety.org.uk/products/filters/Swahili%20(Kiswahili)/
http://www.bibleresources.org.uk/
You can read a brief information about the Swahili language and the Bible translation to that language at Bible Society website. You can also find Swahili Bibles on this website.
Bible Society of Kenya
https://shop.biblesociety-kenya.org/product-category/swahili-bibles/
https://shop.biblesociety-kenya.org
Christianbook
Swahili Bible (Union Version)
https://www.christianbook.com/swahili-bible/9789966405050/pd/8769273
Digital Bible Society
Ethnic Harvest
http://www.ethnicharvest.org/bibles/swahili.htm
Koorong
Swahili Bible
https://www.koorong.com/product/swahili-bible_9789966405296
Multi-Language Media
Swahili Bibles (Case of 20)
https://multilanguagemedia.org/shop/swahili-bible-case-quantity/
https://multilanguagemedia.org
Scripture Earth
The Bible in Swahili
https://www.scriptureearth.org
The KJV Store
Swahili Language Bible - Union Translation 1997
World Bible