The interpreter will be sponsored by Chorley-based Family Care, a foster care and special needs provide.
The BSL interpreter will travel on specific Santa Specials run by ELR between Rawtenstall and Bury from 29 November until Christmas Eve.
Interpreter Marie Marshall said she was “really looking forward” to being part of the team.
The ELR was closed to passengers by British Rail in 1972. It was rebuilt later that same decade, continuing into the 1980s, and reopened between Bury and Ramsbottom in 1987. It was later extended to Rawtenstall and Heywood.
The 12.5 mile (20km) heritage route runs through the scenic Irwell Valley, passing through a landscape dotted with industrial relics, factories, fields and cottages.