The Fugitive Offenders and Mutual Legal Assistance in Criminal Matters Legislation (Amendment) Bill 2019 (Chinese: 2019年逃犯及刑事事宜相互法律協助法例（修訂）條例草案) was a proposed bill regarding extradition to amend the Fugitive Offenders Ordinance (Cap. 503) in relation to special surrender arrangements and the Mutual Legal Assistance in Criminal Matters Ordinance (Cap. 525) so that arrangements for mutual legal assistance can be made between Hong Kong and any place outside Hong Kong. The bill was proposed by the Hong Kong government in February 2019 to establish a mechanism for transfers of fugitives not only for Taiwan, but also for Mainland China and Macau, which are currently excluded in the existing laws.

The introduction of the bill caused widespread criticism domestically and abroad from the legal profession, journalist organisations, business groups, and foreign governments fearing the erosion of Hong Kong's legal system and its built-in safeguards, as well as damage to Hong Kong's business climate. Largely, this fear is attributed to China's newfound ability through this bill to arrest voices of political dissent in Hong Kong. There have been multiple protests against the bill in Hong Kong and other cities abroad. On 9 June, protesters estimated to number from hundreds of thousands to more than a million marched in the streets and called for Chief Executive Carrie Lam to step down. On 15 June, Lam announced she would 'suspend' the proposed bill. Ongoing protests called for a complete withdrawal of the bill and subsequently the implementation of universal suffrage, which is promised in the Basic Law. On 4 September, after 13 weeks of protests, Lam officially promised to withdraw the bill upon the resumption of the legislative session from its summer recess. On 23 October, Secretary for Security John Lee announced the government's formal withdrawal of the bill.

In early 2018, 19-year-old Hong Kong resident Chan Tong-kai murdered his pregnant girlfriend Poon Hiu-wing in Taiwan, then returned to Hong Kong. Chan admitted to Hong Kong police that he killed Poon, but the police were unable to charge him for murder or extradite him to Taiwan because no agreement is in place. The two ordinances in Hong Kong, the Fugitive Offenders Ordinance and Mutual Legal Assistance in Criminal Matters Ordinance, were not applicable to the requests for surrender of fugitive offenders and mutual legal assistance between Hong Kong and Taiwan. The pro-Beijing flagship party Democratic Alliance for the Betterment and Progress of Hong Kong (DAB) chairwoman Starry Lee and legislator Holden Chow pushed for a change to the extradition law in 2019 using the murder case as rationale. In February 2019, the government proposed changes to fugitive laws, establishing a mechanism for case-by-case transfers of fugitives by the Hong Kong Chief Executive to any jurisdiction with which the city lacks a formal extradition treaty, which it claimed would close the "legal loophole". Chen Zhimin, Zhang Xiaoming, and Han Zheng of the PRC publicly supported the change and stated that 300 fugitives were living in Hong Kong. Beijing's involvement in the proposed bill caused great concerns in Hong Kong.

The key provisions of the bill, as originally tabled, are as follows:
In the Fugitive Offenders Ordinance (FOO) (Cap. 503):

And in the Mutual Legal Assistance in Criminal Matters Ordinance (MLAO) (Cap. 525):

Opposition expressed fears that the city would open itself up to the long arm of mainland Chinese law, putting people from Hong Kong at risk of falling victim to a different legal system. It therefore urged the government to establish an extradition arrangement with Taiwan only, and to sunset the arrangement immediately after the surrender of Chan Tong-kai.

The business community also raised concerns over the mainland's court system. The Liberal Party and the Business and Professionals Alliance for Hong Kong (BPA), the two pro-business parties, suggested 15 economic crimes being exempted from the 46 offences covered by the extradition proposal. The American Chamber of Commerce in Hong Kong (AmCham) pointed out that the mainland's "criminal process is plagued by deep flaws, including lack of an independent judiciary, arbitrary detention, lack of fair public trial, lack of access to legal representation and poor prison conditions". The government responded to business chambers' concerns by exempting nine of the economic crimes originally targeted. Only offences punishable by at least three years in prison would trigger the transfer of a fugitive, up from the previously stated one year. Nonetheless, these amendments failed to assuage the business community's concerns. According to the CBC, "[What the] rich business people fear is that the extradition law would destroy the freedoms people and businesses in the territory have grown to expect". Due to the vast power that politicians and officials exert over the mainland legal system, "businesses that want contracts in China to be respected typically include a provision that allows for any disputes to be resolved under Hong Kong law", thereby making Hong Kong a safe and stable haven for multinational corporations. The proposed extradition law would jeopardise Hong Kong's status, with some companies already considering relocation to Singapore. However, the pro-business parties in the Legislative Council later agreed to support the government bill. The situation was similar to the 2017 Chief Executive Election, in which the business sectors were requested to support Carrie Lam under the pressure from the Beijing's Authority.

On 1 April, Hong Kong billionaire tycoon Joseph Lau, former chair of the Chinese Estates Holdings who was convicted of bribery and money laundering in a land deal in Macau in 2014, applied for a judicial review over the bill in court. Lau's lawyers asked the court to make a declaration that the surrender of Lau to Macau would contravene the Hong Kong Bill of Rights. Lau made an abrupt U-turn and dropped his legal challenge on 29 May, saying that he "loves his country and Hong Kong" and that he now supported the legislation.