The International Labor Organization (ILO) is a specialized U.N. agency which "seeks the promotion of social justice and internationally recognized human and labour rights." The ILO, together with its Member States, sets standards in the form of binding conventions and non-binding recommendations. The ILO Conventions and recommendations of the ILO Committee of Experts on the Application of Conventions and Resolutions (CEACR) have addressed sexual harassment primarily as a form of discrimination in the workplace. Sexually harassing conduct may also be deemed a violation of the right to safe and healthy working conditions guaranteed under ILO Conventions. 

The major ILO convention addressing sex discrimination is Discrimination (Employment and Occupation) Convention (No. 111) which entered into force in 1960. It defines discrimination to include "any distinction, exclusion or preference made on the basis of . . . sex . . . which has the effect of nullifying or impairing equality of opportunity or treatment in employment or occupation." Member states that have ratified this convention undertake to promote equality of opportunity and treatment by enacting legislation and cooperating with employers' and workers' organizations. This convention does not explicitly mention sexual harassment, although a 2003 General Observation concerning Convention No. 111 by the CEACR reminds states that "sexual harassment is a form of sex discrimination and should be addressed within the requirements of the Convention." In surveying national legislation on sexual harassment, the Committee has found that the various definitions of sexual harassment

contain the following key elements: (1) (quid pro quo): any physical, verbal or non-verbal conduct of a sexual nature and other conduct based on sex affecting the dignity of women and men, which is unwelcome, unreasonable, and offensive to the recipient; and a person's rejection of, or submission to, such conduct is used explicitly or implicitly as a basis for a decision which affects that person's job; or (2) (hostile work environment): conduct that creates an intimidating, hostile or humiliating working environment for the recipient.

CEACR recommends that countries adopt measures to address sexual harassment and in doing so, asks them to include the following information in their reports to the Committee: whether and how sexual harassment has been prohibited; the definition of sexual harassment used; the scope of who is protected; the scope of the protection; the scope of liability; administrative mechanisms in place; enforcement mechanisms and procedures; court decisions, educational and awareness-raising measures; and cooperation with employers' and workers' organizations in addressing sexual harassment through policies and collective agreements.

The only ILO Convention or Recommendation that explicitly refers to sexual harassment (or even harassment) is the Indigenous and Tribal People Convention (No. 169) (entered into force in 1991). Article 3 states: "The measures taken shall include measures to ensure: . . . (d) that workers belonging to these peoples enjoy equal opportunities and equal treatment in employment for men and women, and protection from sexual harassment."

In 1998, the ILO issued the Declaration on Fundamental Principles and Rights at Work. This declaration, although it does not directly address sexual harassment, reaffirms the ILO commitment to the elimination of discrimination in the workplace:

[A]ll Members, even if they have not ratified the Conventions in question, have an obligation arising from the very fact of membership in the Organization to respect, to promote and to realize, in good faith and in accordance with the Constitution, the principles concerning the fundamental rights which are the subject of those Conventions, namely: . . . (d) the elimination of discrimination in respect of employment and occupation.

The ILO Convention No. 155 (Occupational and Health), as amended by the 2002 Protocol, and the ILO Convention No. 161 (Occupational Health Services) require states which are parties to the conventions to take certain actions to prevent sexual harassment because such conduct may be harmful to the physical and mental health of its workers.

• Article 4 of Convention No. 155 requires each party to the convention to "formulate, implement and periodically review a coherent national policy on occupational safety, occupational health and the working environment" together with representative organizations of employers and workers. The goal of the policy must be to "prevent accidents and injury to health arising out of, linked with or occurring in the course of work, by minimising, so far as is reasonably practicable, the causes of hazards inherent in the working environment." The convention defines health to include "the physical and mental elements affecting health which are directly related to safety and hygiene at work." The physical and mental injuries associated with sexual harassment would clearly qualify as injuries to health under the conventions. Likewise, sexual harassment may be deemed a hazard inherent in the work environment the effect of which ILO Member States must make an effort to minimize.
• The General Conference of the International Labor Organization has issued Recommendation No. 164 which specifies particular strategies for minimizing hazards in the work environment as required under the Convention 155 which may be helpful to policy makers addressing the problem of sexual harassment.
• Convention No. 161 discusses "the requirements for establishing and maintaining a safe and healthy working environment which will facilitate optimal physical and mental health in relation to work." Among these requirements are (1) the obligation "to develop progressively occupational health services for all workers" and (2) the obligation to establish such services where none have yet been established. Such services might encompass counseling and training services related to sexual harassment.

It is worth noting that Article 22 of the Constitution of the International Labor Organization requires each Member State to make an annual report to the International Labor Office on "measures which it has taken to give effect to the provisions of Conventions to which it is a party." This obligation would apply to parties to the conventions described above. The report forms are available at the following website: http://www.ilo.org/ilolex/english/reportforms/reportformsE.htm. Recent Article 22 reports are available at the following website: http://webfusion.ilo.org/public/db/standards/normes/appl/index.cfm?lang=EN.

In 2005, the ILO issued a report, Sexual harassment at work: National and international responses, which is a comprehensive survey of international and national efforts to combat sexual harassment in the workplace, as well as a review of the activities of employers’ and workers’ organizations, and NGO’s. The report “attempts to identify the main approaches being taken, to highlight dominant trends and to single out best practices.”  The ILO views this report as furthering the goals of its organization, stating:  “Sexual harassment is a hazard encountered in workplaces across the world that reduces the quality of working life, jeopardizes the well-being of women and men, undermines gender equality and imposes costs on firms and organizations. For the International Labour Organization, workplace sexual harassment is a barrier towards its primary goal of promoting decent working conditions for all workers.”

The report found that sexual harassment is widespread in countries where research has been conducted, and that it predominantly impacts women, although the practice can impose significant costs on both victims and their employers.  Additionally, the report notes that most legislation prohibiting sexual harassment has been passed since 1995 and the report identifies “signs of an emerging trend towards enacting specific laws against sexual harassment which draw on both civil and criminal law approaches; of imposing duties on employers and holding them liable for the actions of their employees, and of tailoring enforcement procedures so that they do not discourage individuals from bringing claims. The role of laws in encouraging employers to introduce workplace policies is also increasingly influencing their content. . . . Moreover, there appears to be an emerging consensus around what workplace policies should contain and the steps to be taken to implement them, which can be drawn on by those employers who have yet to take action.”