Background : Research using nonmigrant samples indicates that having a partner and children is protective against loneliness. Such beneficial effects may be weaker for migrants with partners and/or children living in different countries. Objective : We assess how feelings of loneliness among Polish migrants in the Netherlands compare to levels among the general Dutch population and how migrants' feelings of loneliness vary by presence and location of partners and offspring. Methods : We used weighted data from the Families of Poles in the Netherlands survey (n=1,129). Wald tests were used to compare levels of loneliness among Polish migrants with scores reported in a different study for the general Dutch population. Linear regression was used to estimate how presence and location of partners and children were associated with loneliness. Results : Polish migrants in the Netherlands were lonelier than the general Dutch population. Among men, those who had been in the Netherlands for longer were lonelier than those who had more recently arrived. Unpartnered men and men with a partner living abroad were lonelier than men with a partner living in the Netherlands. For women, no effects of presence and location of a partner were found. Presence and location of children made little difference. Conclusions : Although loneliness is often considered a problem for older individuals, feelings of loneliness are also strong among working-age Polish migrants. Consistent with studies on nonmigrant samples, we found that men with a partner were less lonely than unpartnered men, but only when the partner also resided in the Netherlands. Contribution : [see conclusions]