Buckminster Fuller

Extremely influential architect, thinker and designer, active in arcology-thinking in the 60s thru 80s
East St. Louis and the Old Man River Project – History and Headlines
1985 Critical Path (book) – Wikipedia
It sounds like a lot of the ideas for the Venus project came from Buckminster Fuller. He might be the originator of the Arcology idea
“You never change things by fighting the existing reality. To change something, build a new model that makes the existing model obsolete.”

Paolo Soleri

Wikipedia
wrote a few books on arcologies, the first one in the 70s. Apparently he was the one who coined the term Arcology (Architecture + Ecology)
- Arcosanti – Wikipedia
  - designed by Paolo Soleri, a famous architect, Arcosanti is an experimental “arcology prototype”, a demonstration project under construction in central Arizona since 1970
  - Arcosanti.org