Bakhtiar Mohd Nor (died) Pakatan Harapan (BERSATU) Zakaria Hanafi Barisan Nasional (UMNO) A by-election was held on 2 March 2019 for the Selangor State Legislative Assembly seat of Semenyih.

[5] The Pan-Malaysian Islamic Party (PAS) had announced that they would make way for Barisan Nasional (BN) to contest in the by-election as the latter had more support in the constituency.

[6] The previous BN election candidate Datuk Johan Abd Aziz of United Malays National Organisation (UMNO) who was also the former Semenyih assemblyman for two terms earlier before losing in GE14 to BERSATU, said on 22 January 2019 that he will not be contesting in the by-election.

[8] Socialist Party of Malaysia (PSM) on 13 February officially announced that Youth Member, Nik Aziz Afiq Abdul as their candidate for the by-election.

[11] Social activist Kuan Chee Heng also known as "Uncle Kentang" or even "10-sen man" announced in his Facebook page that he will contest as an independent candidate.

[17] In a statement on 14 February, Chief Secretary to the Government Datuk Seri Dr Ismail Bakar said the Yang di-Pertuan Agong, Al-Sultan Abdullah Ri’ayatuddin Al-Mustafa Billah Shah, had on 14 February approved University of Malaya Law Faculty lecturer Dr Azmi Sharom's appointment as Election Commission (EC) deputy chairman and also approved the appointment of four EC members; Datuk Seri Ramlan Ibrahim, Datuk Chin Phaik Yoong, Dr Faisal S. Hazis and Zoe Randhawa.

[18] On 25 February, the High Court rejected the petition filed and dismissed the bid to stop the Semenyih by-election; allowing it to continue as planned.

[23] Papagomo was charged on 28 February 2019 with two counts of intending to insult the modesty of the minister by saying to him 'ko bodoh' (you are stupid) and with voluntarily causing hurt on Syed Saddiq.