Zilliacus
is a Finland-Swedish surname that may refer to
- Benedict Zilliacus, Finnish journalist, author, scriptwriter and translator
- Bruno Zilliacus, Finnish athlete
- Jutta Zilliacus, Finnish-born Estonian journalist, author and politician
- Konni Zilliacus (senior), Finnish politician, author and independence activist
- Konni Zilliacus, Finnish-born British politician
- Linda Zilliacus, Finnish actress
- Thomas Zilliacus, Finnish businessman
- Tobias Zilliacus, Finnish actor