Background: Adult vaccination, crucial for preventing diseases like Hepatitis B, influenza, COVID-19, and HPV-related cancers, remains underutilized in India, particularly in rural regions like Himachal Pradesh, due to knowledge gaps, misconceptions, and access barriers. This study aimed to evaluate public awareness of adult vaccination, focusing on Hepatitis B, flu, COVID-19 boosters, and HPV, among adults in Himachal Pradesh, with an emphasis on rural communities. Materials and Methods: A descriptive, cross-sectional online survey was conducted from January to March 2025 , targeting adults aged 18–65 years in Himachal Pradesh. A bilingual (Hindi/English) questionnaire, hosted on Google Forms, assessed socio-demographic factors, vaccination knowledge, attitudes, and barriers. Using convenience sampling, 480 participants completed the survey. Data were analyzed with IBM SPSS Statistics v27.0, with knowledge scores categorized as Very Good (≥80%), Good (60–79%), Fair (40–59%), and Poor (<40%). Results: Participants, primarily aged 18–35 years (72.9%) and female (55.0%), showed moderate awareness: 80.0% recognized adult vaccines prevent serious diseases, 75.0% identified Hepatitis B’s liver disease link, and 82.9% noted cost as a barrier. Gaps existed in flu vaccine frequency (60.0%), asymptomatic Hepatitis B (64.0%), and HPV infection (62.9%). Knowledge levels were Very Good (27.9%), Good (46.0%), Fair (20.0%), and Poor (6.1%). Limited healthcare access (32.1%) highlighted rural challenges. Conclusion: While awareness of adult vaccination is improving, knowledge gaps and barriers like cost and access persist in Himachal Pradesh. Targeted education, subsidized vaccines, and rural outreach are critical to enhancing uptake and reducing disease burden.