Introduction: The Sustainable Development Goals of the United Nations include a commitment to “leave no one behind” as a universal goal. To achieve this in geriatric oncology (GO) worldwide, it is important to understand the current state of GO at an international level. The International Society of Geriatric Oncology (SIOG) has several National Representatives (NRs) who act as SIOG's delegates in their respective countries. The NRs took part in this international survey exploring the state of GO practice, identifying barriers and solutions. Materials and Methods: The NRs answered open-ended questions by email from February 2020 to October 2022. The questionnaire domains included the demographic information of older adults for their countries, and the NRs' opinions on whether GO is developing, what the barriers are to developing GO, and proposed actions to remove these barriers. The demographic data of each country reported in the survey was adjusted using literature and database searches. Results: Twenty-one of thirty countries with NRs (70%) participated in this questionnaire study: 12 European, four Asian, two North American, two South American, and one Oceanian. The proportion of the population aged ≥75 years varied from 2.2% to 15.8%, and the average life expectancy also varied from 70 years to 86 years. All NRs reported that GO was developing in their country; four NRs (18%) reported that GO was well developed. Although all NRs agreed that geriatric assessment was useful, only three reported that it was used day-to-day in their countries' clinical practice (14%). The major barriers identified were the lack of (i) evidence to support GO use, (ii) awareness and interest in GO, and (iii) resources (time, manpower, and funding). The major proposed actions were to (i) provide new evidence through clinical trials specific for GO patients, (ii) stimulate awareness through networking, and (iii) deliver educational materials and information to healthcare providers and medical students. Discussion: This current survey has identified the barriers to GO and proposed actions that could remove them. Broader awareness seems to be essential to implementing GO. Additional actions are needed to develop GO within countries and can be supported through international partnerships.