Even though the COVID-19 pandemic is a global phenomenon that is heavily affecting the lives, livelihoods, and wellbeing of the entire population, the degree and severity of its effects are different among groups and sectors. In developing countries, where there is poor infrastructure coupled with a low level of education and a high incidence of poverty, the pandemic would result in increased unemployment, decreased income for daily labor, increased food insecurity, depletion of saving and relief measures, and disrupted the marketing system, among others. Recently, some studies have been conducted in Ethiopia regarding the impact of the pandemic on the people and the country as a whole by reviewing the literature and mobile call surveys. However, those studies fail to capture the representative sample and empirical data to forward informed decisions. To this end, the present study has investigated the effect of COVID-19 on the livelihood activities of smallholder farm households in South Wollo and Oromia administrative Zones, Ethiopia. A multistage random sampling procedure was employed to draw 275 respondents out of 32,214 household heads. Data were collected through interview schedules, key informants and case studies from September to November 2020. Descriptive statistics, econometric analysis and qualitative approaches were employed to analyze the data. The major livelihood activities in the study area are crop production (97.4%), livestock rearing (77.4%), daily work (47%), small business (31.4%), livestock trading (30.7%), remittance (24.8%), labor migration (14.8%), sale of firewood (11.1%) and income from Productive Safety Net Program (PSNP) (17%). The study shows that the livelihoods of 88.89% of the households were affected by the pandemic. The pandemic significantly affected and forced households to cease their livelihood activities such as daily labor (34.82%), small business trade (26.3%), livestock trading (23.7%), income from remittance (21.49%) and labor migration (11.48%). This implies that the pandemic particularly affected non-farm and off-farm livelihood diversification strategies. Therefore, the government and other rural development partners should focus on immediate and long-term intervention strategies to recover the most affected households through social security programs, creating market linkage and revolve funding mechanisms.