No state-mandated paid sick leave
Missouri does not require employers to provide paid sick leave. The Missouri Department of Labor and Industrial Relations confirms that employers are not required to offer paid sick leave or any other type of paid fringe benefit; provision of such benefits is left to employer discretion or contract.
Jury duty leave protection
Missouri law prohibits employers from terminating, disciplining, threatening, or taking any adverse action against an employee because that employee received or responded to a jury summons. Employees may not be required or requested to use annual, vacation, personal, or sick leave for time spent responding to a jury summons, participating in jury selection, or serving on a jury. An employee discharged in violation of this protection may bring a civil action within 90 days for recovery of lost wages, other damages, reinstatement, and reasonable attorney's fees if the employee prevails.
Source: Mo. Rev. Stat. § 494.460
Voting leave — three-hour paid entitlement
Missouri entitles any person eligible to vote in an election held within the state to absent himself from services or employment for a period of three hours between the opening and closing of the polls for the purpose of voting. The statute prohibits discharge or threat of discharge for such absence, and bars any deduction from the employee's usual salary or wages on account of the absence, provided the employee votes. The employee may not be made "liable to any penalty" because of the absence.
Three-successive-hour exception
The three-hour entitlement does not apply to a voter on election day if there are three successive hours while the polls are open in which the voter is not in the service of his employer. For example, if Missouri polls open at 6:00 a.m. and close at 7:00 p.m., an employee whose shift runs 9:00 a.m. to 5:00 p.m. has three successive non-work hours available (6:00–9:00 a.m. or, depending on the employee's end time, potentially after 4:00 p.m.) and would not trigger the statutory leave entitlement.
Prior-notice requirement
Request for leave must be made prior to the day of election. The statute does not specify how far in advance, the form of the request, or whether the employer may designate the particular hours (e.g., beginning or end of shift) during which the three-hour absence occurs.
Scope of protection
Mo. Rev. Stat. § 115.639 bars discharge, threat of discharge, and any deduction from wages. The phrase "shall not...be liable to any penalty" appears in the statute but is not further defined; whether this extends to written warnings, performance documentation, or other employer actions beyond termination and wage deductions has not been addressed in published Missouri case law or administrative guidance as of this writing.
Source: Mo. Rev. Stat. § 115.639