1. Title VII of the Civil Rights Act of 1964
Forbids employers from discriminating against job applicants and employees based on their race, color, national origin, sex or religion. 
An employer cannot retaliate against an employee for objecting to discrimination under Title VII, reporting discrimination, filing a discrimination charge or participating in a discrimination legal proceeding.
Employers with 15 or more employees must adhere to Title VII.
2. The Age Discrimination in Employment Act (ADEA)
Prohibits discrimination based on their age against job applicants and employees who are 40 years or older.
Under the ADEA, these individuals cannot be retaliated against for opposing the employer's discriminatory actions, filing a discrimination charge or participating in a discrimination proceeding.
The ADEA covers employers with 20 or more employees.
3. The Americans with Disabilities Act (ADA)
Makes it illegal for employers to discriminate against job applicants and employees with disabilities.
Title V of the ADA prohibits employers from retaliating against qualified individuals who object to the employer's unlawful practices or have "made a charge, testified, assisted, or participated in any manner in an investigation, proceeding, or hearing under this chapter."
The ADA applies to employers with 15 or more employees.
4. The Equal Pay Act (EPA)
Requires that employers compensate men and women equally for performing the same work at the same location.
Designed to eliminate gender-based wage discrimination, the EPA also forbids employers from retaliating against employees who exercise their rights under the act.
All employers must comply with the EPA.
5. The Fair Labor Standards Act (FLSA)
Establishes federal minimum wage, overtime, child labor and recordkeeping standards.
In addition, the FLSA protects employees who have filed FLSA-related complaints from retaliation. Among other things, an employer cannot retaliate against an employee for participating in a Department of Labor audit, testifying in a legal proceeding, filing a wage complaint or communicating with Wage and Hour Division investigators.
The FLSA covers most private-sector employers.
6. The Occupational Safety and Health Act (OSHA)
Sets federal health and safety standards to protect people on the job.
Per Section 11(c) of the OSHA, it is unlawful for employers to retaliate against employees who assert their rights under the act — such as by complaining about unsafe or unhealthy working conditions. OSHA also oversees more than 20 whistleblower protection laws.
Any employee can file a complaint with OSHA if he or she believes his or her employer violated a retaliation or whistleblower law that OSHA administers.
7. The Family Medical and Leave Act (FMLA)
Requires covered employers to provide unpaid, job-protected leave to eligible employees.
Under the FMLA, employees cannot be punished for exercising their FMLA rights, including taking FMLA leave.
The FMLA applies to employers that have 50 or more employees during at least 20 weeks of the year.
Employers should consider other federal laws — such as the National Labor Relations Act and Title II of the Genetic Information Nondiscrimination Act (GINA) — plus any state laws that protect employees from retaliation. In fact, this is just a brief intro to a wide range of laws, and regulations are always changing. The bottom line? Work closely with legal and HR experts.