United States (U.S.) and global experts recommend that populations reduce red and processed meat (RPM) intake and transition to plant-rich, sustainable diets to support human and planetary health. A systematic scoping review was conducted to identify the landscape of media campaigns that promote plant-rich dietary patterns, traditional plant proteins, and novel plant-based meat alternatives (PBMA) and that encourage or discourage RPM products to Americans. Of 8321 records screened from four electronic databases, 103 records were included, along with 62 records from gray literature sources. Across 84 media campaigns (1917–2023) identified, corporate marketing campaigns (58.6%) were most prevalent compared to public information (13.8%), corporate sustainability (12.6%), countermarketing (5.7%), social marketing (4.6%), and public policy (4.6%) campaigns. Findings indicate that long-running corporate RPM campaigns, many with U.S. government oversight, dominated the landscape for decades, running alongside traditional plant protein campaigns. Novel PBMA campaigns emerged in the past decade. Many civil society campaigns promoted plant-rich dietary patterns, but few utilized social norm or behavior change theory, and only the Meatless Monday campaign was evaluated. The U.S. government, academia, businesses, and civil society should commit more resources to and evaluate the impact of media campaigns that support a sustainable diet transition for Americans, restrict and regulate the use of misinformation in media campaigns, and prioritize support for plant-based proteins and plant-rich dietary patterns.