Ghosh will join Smriti Mandhana (Southern Brave) and Harmanpreet Kaur (Trent Rockets) in the competition next month, who were retained from last year's squad and signed in March's draft, respectively.
Active male Indian players are not permitted to play in overseas short-form leagues by the BCCI but female players have regularly appeared in the Hundred and the Women's Big Bash League, among others.
Ghosh's salary in the Hundred is understood to be £12,500 (INR 13 lakh approx.), which pales in comparison to the INR 1.9 crore (£180,000 approx.) that she was paid by Royal Challengers Bangalore in the inaugural Women's Premier League earlier this year.
Spirit have also found short-notice replacements for Glenn Maxwell and Mitchell Marsh, after they were pulled out of the tournament by Cricket Australia. Matthew Wade, the Australian wicketkeeper-batter, and New Zealand's Daryl Mitchell will come in instead.
Women's Hundred signings:
Birmingham Phoenix: Davina Perrin, Abbey Freeborn, Charis Pavely
London Spirit: Richa Ghosh (replacing Georgia Redmayne), Lauren Filer, Chloe Hill, Alice Monaghan
Manchester Originals: Ami Campbell, Amara Carr, Mahika Gaur, Laura Jackson
Northern Superchargers: Georgie Boyce, Lucy Higham, Grace Ballinger, Grace Hall, Leah Dobson (replacing Phoebe Franklin)
Oval Invincibles: Sophia Smale, Beth Langston, Cordelia Griffith, Claudie Cooper, Lizzie Scott (replacing Tash Farrant)
Southern Brave: Kalea Moore, Seren Smale, Ellie Anderson, Mary Taylor
Trent Rockets: Jo Gardner, Fran Wilson, Nat Wraith, Cassidy McCarthy (replacing Emma Jones)
Welsh Fire: Emily Windsor, Ella McCaughan, Georgia Davis, Kate Coppack
Men's Hundred replacements:
London Spirit: Matthew Wade (replacing Glenn Maxwell), Daryl Mitchell (replacing Mitchell Marsh)
Manchester Originals: Usama Mir (replacing Wanindu Hasaranga)
Northern Superchargers: Matthew Short (replacing Michael Bracewell)
Oval Invincibles: Tom Lawes (replacing Saqib Mahmood), Adam Zampa (partially replacing Sunil Narine)