Robert Frank Onder Jr.[1][2] (born January 6, 1962) is an American politician, attorney, and physician from the state of Missouri.

Onder subsequently graduated from Washington University School of Medicine,[7] and is a physician specializing in allergy and asthma care.

In 2008, Onder left the state legislature to run for the US House in Missouri's 9th congressional district, where incumbent Kenny Hulshof was not seeking re-election.

Onder distinguished himself as one of the more fiscally conservative candidates, emphasizing his free-market voting record in the Missouri House and earning the endorsement of the Club for Growth.

[12] In 2014, Onder ran for the Missouri Senate in the 2nd district, defeating Chuck Gatschenberger and Vicki Schneider in the Republican primary.

[17] The bill forbids the creation of sanctuary cities in Missouri, allows for cancellation of state contracts for contractors who hire people illegally present in the United States, and requires public agencies to verify the legal status of immigrants before providing social service benefits.

The bill passed the State House and Senate with strong support and was signed into law by Matt Blunt.

In 2016, Onder introduced Senate Joint Resolution 39, a proposed amendment to the Missouri Constitution that would protect wedding industry businesses that refuse to serve LGBTQIA+ couples.

[24] Onder was an outspoken supporter of HB 1562,[25] a bill that expanded the crime of sex trafficking to include the advertisement of minors for prostitution or pornography.

[26] Onder, who is anti-abortion, was the original author of legislation that requires annual, unannounced state inspections of healthcare clinics that provide reproductive healthcare; bars clinics from instructing ambulances to silence their sirens or turn their lights off; mandates that pathologists test fetal tissue; enacts whistleblower protections for employees of abortion clinics; and exempts pregnancy resource centers from a St. Louis ordinance[27] barring discrimination over reproductive choices.

[31] In 2019, Onder strongly pushed for the Missouri Stands for the Unborn Act, a bill that banned abortion at eight weeks of pregnancy or later.

[40] In 2017, Onder was the Senate handler for HB 130,[41] a bill that creates a statewide regulatory framework for transportation networking companies.

"It disrupts the single mom, the senior citizens, the working parents day and their week these unnecessary and costly inspections," Onder stated.

[46] In 2020, Onder introduced SB 560, a bill that would grant state licensing reciprocity to nonresident military spouses.

"[48] In 2019, Onder introduced legislation to allow people with concealed carry permits to bring a firearm onto public transit.