Don had siblings:
- Bruce Johnstone (1931 - 2 December 2002) 
- Richard Johnstone (1939 - 19 September 2009) of Abbotsford , a millwright with Great Lakes Paper (Bowater) in Thunder Bay
- Grace Giesbrecht (Dan)
- Jean Lightfoot (John) of British Columbia
Don had children by a woman called Sonja:
- Don Junior (10 August 1959 - 2 March 2019) 
Later he married a woman called Martha.
According to Nancy Greenwald, Don had three kids:
- Jan (Gordon) (1968 - 2011 ?)
In the 1990s his children practiced the bagpipes in his backyard.
 JOHNSTONE, Jan Gordon Jan was born in Thunder Bay, Ontario on May 3, 1968. Jan died suddenly on Sunday, December 10, 2011