| Office3: | Minister of Transport |
| Primeminister3: | Jim Marurai |
| Term Start3: | 26 December 2009 |
| Term End3: | 2 December 2010 |
| Predecessor3: | Tangata Vavia |
| Successor3: | Tom Marsters |
| Office4: | Minister for Infrastructure and Planning |
| Term Start4: | 26 December 2009 |
| Term End4: | 2 December 2010 |
| Predecessor4: | Tangata Vavia |
| Successor4: | Teariki Heather |
| Constituency Mp5: | Ruaau |
| Parliament5: | Cook Islands |
| Term Start5: | 27 September 2006 |
| Term End5: | 1 August 2022 |
| Predecessor5: | Vaine Wichman |
| Successor5: | Timi Varu |
| Birth Date: | 1958 7, df=yes |
| Birth Place: | Rarotonga |
| Party: | Cook Islands Democratic Party |
William Kati (Smiley) Heather (born 7 July 1958)[1] is a Cook Islands politician and former Cabinet Minister. He represented the seat of Ruaau in the Cook Islands Parliament from 2006 to 2022 and is Deputy Leader of the Cook Islands Democratic Party. He is the older brother of Cook Islands Party MP Teariki Heather.[2]
Heather was born in Rarotonga and educated at Arorangi Primary School and Tereora College in the Cook Islands and Onslow College in Wellington, New Zealand.[3] From 1980 to 1997 Heather played for the Cook Islands national rugby union team. He worked as a public servant in the Cook Islands Ministry of Works, Energy and Physical Planning (MOWEPP) from 1992, and in 1997 became Director of Road Works.[3] He was elected to Parliament as a member of the Democratic Party in the 2006 snap election. Following the election, he was appointed Democratic Party whip.
In December 2009 he was appointed to Cabinet as Minister for Transport, Infrastructure & Planning, and Energy[4] following the sacking of Terepai Maoate and resignation of Democratic party cabinet ministers.[5] As a result, he was expelled from the Democratic Party on 8 April 2010.[6]
He was re-elected at the 2010 election as a Democratic candidate. In August 2012 he was elected Deputy Leader of the Democratic party.[7] He was re-elected in the 2014 election, and in April 2015 was elected leader of the Democratic Party.[8] In June 2017 he became leader of the opposition again.[9]
Heather was re-elected at the 2018 election. In February 2020 he was appointed Democratic Party spokesperson for Corrective Services, Infrastructure and the Public Service Commission.[10] In march 2021 he was appointed deputy leader, replacing Terepai Maoate Jnr.[11]
He lost his seat in the 2022 Cook Islands general election.[12]