Street markets can contribute to food security, since they are a source of fresh food and comparably inexpensive goods, being very relevant for low-income groups. Their relevance is even higher when considering older people, due to their often-constrained financial resources and possibilities to move. To assess the potential contribution of street markets to food security, this paper aims at evaluating to what extent older people have access to such a relevant asset. We consider the case of Chile, an ageing country with an unequal pension system, which makes it relevant for older people to access healthy and inexpensive food. We analyze what proportion of older people (i.e., people over 65) has walking access within 10 min to a street market—feria libre—in each Chilean region, with particular detail in the country’s four major urban areas. We compare the resulting accessibility maps with census data to identify neighborhoods with higher proportions of older people and examine their socio-economic conditions. Our findings show that while street markets are less accessible to older people in comparison to the general population, the inhabitants who can access them belong mainly to low-income groups. The results provide relevant insights to develop neighborhood-based policies for spreading and strengthening street markets, especially in low-income areas with insufficient levels of access to other relevant urban opportunities.