Kesepian menjadi masalah yang mungkin dialami emerging adults yang tinggal seorang diri di masa pandemi COVID-19. Dukungan sosial daring menjadi salah satu faktor yang mungkin dapat berperan dalam mengatasi kesepian di masa pandemi. Penelitian bertujuan untuk menguji pengaruh dukungan sosial daring terhadap kesepian emerging adults yang tinggal seorang diri di pulau Jawa. Partisipan penelitian berjumlah 247 orang dan direkrut menggunakan purposive dan snowball sampling. Dukungan sosial daring diukur menggunakan Online Social Support Scale dan kesepian diukur menggunakan UCLA Loneliness Scale Version 3. Data dianalisis menggunakan analisis regresi, korelasi bivariat dan parsial Spearman. Didapatkan beberapa hasil penelitian, (1) dukungan sosial daring secara signifikan memprediksi kesepian; (2) dukungan sosial daring dan kesepian berkorelasi, bahkan saat mengontrol faktor kedekatan dan aktivitas luring; (3) seluruh dimensi dukungan sosial daring dan intensitas waktu daring berkorelasi dengan kesepian, dan (4) intensitas waktu daring berkorelasi dengan dukungan sosial daring. Penelitian ini menyarankan emerging adults yang tinggal seorang diri di pulau Jawa pada masa pandemi COVID-19 memanfaatkan media sosial untuk memperoleh dukungan sosial daring untuk menghadapi kesepian. / During the COVID-19 pandemic, emerging adults who are living alone may experience loneliness. Online social support is one of the factors that might play a role in overcoming loneliness during the pandemic. This study aims to examine the effect of online social support on loneliness in emerging adults who live alone on the island of Java. There are 247 participants in current study and were recruited using purposive and snowball sampling. Online social support was measured using the Online Social Support Scale and loneliness was measured using the UCLA Loneliness Scale Version 3. Data were analyzed using regression analysis and Spearman’s bivariate and partial correlation. There are several results obtained in this study, (1) online social support significantly predicts loneliness; (2) online social support and loneliness are correlated, even when controlling for closeness and offline activity factors; (3) all dimensions of online social support and time spent online are correlated with loneliness, and (4) time spent online is correlated with online social support. This study suggests that emerging adults who live alone on the island of Java during the COVID-19 pandemic can use social media to get online social support to deal with loneliness.