Colonel William McLellan CBE (1874–1934) was a Scottish electrical engineer. Born in Palnackie, McLellan joined Charles Merz in 1902 to form the Merz & McLellan consulting engineering partnership. In the 1920s, then Colonel McLellan, he designed the Galloway Hydro-Electric Power Scheme.

• Power from the Water, Galloway Hydro website
• Charles Merz- Lessons from Boston
• Tongland Power Station Turns 75