Many companies host an annual Christmas or holiday party which, for many employees, represents a fun, meaningful, and ritualized event closely linked to the organization’s culture. However, the factors that relate to employees’ satisfaction or dissatisfaction with this event, as well as to their positive and negative affect associated with this event, are currently not well understood. Accordingly, the current study aimed to explore how employee characteristics (e.g., demographics, employment characteristics, attitudes), organizational characteristics (i.e., human relations, open systems, rational goal, internal process culture), and event characteristics (e.g., location, activities, heavy drinking, inappropriate behavior of supervisors or colleagues, ritual features) are related to employee happiness. Data were provided by 359 employees from various organizations in Germany, who completed an online survey at the beginning of January 2019. Results showed that a human relations culture, an external location, fun activities, informality, and symbolism predicted higher employee satisfaction with the Christmas party. In contrast, heavy drinking and formality predicted higher dissatisfaction with the Christmas party, and longer organizational tenure, a human relations culture, a speech, providing both alcoholic and non-alcoholic beverages, and symbolism predicted lower dissatisfaction. Furthermore, employee age, organizational identification, involvement in planning, a human relations and an internal process culture, a speech, providing both alcoholic and non-alcoholic beverages, heavy drinking, supervisor and coworker inappropriate behavior, formality, and symbolism were differentially associated with high- and low-arousal positive and negative affect. These findings suggest several directions for future research on company parties and have practical implications for organizations and party planning committees.