By-elections to the Wellington City Council occur to fill vacant seats in the City Council. The death, resignation, bankruptcy or expulsion of a sitting councillor can cause a by-election to occur. By-elections were particularly frequent in the 1980s and 1990s but have become a rarity in recent years with only two occurring since 2000. The most recent by-election in Wellington was in 2017 triggered by deputy mayor Paul Eagle's resignation upon being elected MP for Rongotai.