Dr. Xavier Jayakumar a/l Arulanandam (Tamil: சேவியர் ஜெயக்குமார், romanized: Cēviyar Jeyakkumār; born 1953) is a Malaysian politician and dentist who served as Minister of Water, Land and Natural Resources in the Pakatan Harapan (PH) administration under former prime minister Mahathir Mohamad from July 2018 to the collapse of the PH administration in February 2020, Member of Parliament (MP) for Kuala Langat from May 2018 to November 2022, Member of the Selangor State Executive Council (EXCO) in the Pakatan Rakyat (PR) state administration under former Menteri Besar Khalid Ibrahim from March 2008 to May 2013 and Member of the Selangor State Legislative Assembly (MLA) for Seri Andalas from March 2008 to May 2018.

On 1 May 2019, Xavier gave himself a rating of seven to eight out of 10 for his performance as the Water, Land and Natural Resources Minister in the Pakatan Harapan government, after being in the position for about a year.

[3] On 17 February 2021, a person he described as a fellow party member and "close family friend" was arrested with two others by the Malaysian Anti-Corruption Commission in relation to a contract awarded in 2019 under the jurisdiction of his ministry.

On 13 March 2021, he suddenly announced that he resigned as both a member and as a party vice-president, citing that he was "extremely frustrated" by the events of the past year.

[6] He contested in the 2004 Malaysian general election in the Ampang which saw him lose to Barisan Nasional candidate, Rozaidah Talib.