Pre-service teachers today face challenges and opportunities in increasingly linguistically diverse Swedish schools. The present study aims to understand how pre-service English teachers of Years 4–6 (ages 10–12) plan lessons while considering this linguistic diversity. The focus is on pre-service teachers studying a course, English Language Learning and Teaching, with an analysis of their lesson unit assignments, spotlighting multilingual perspectives in their planning. Language orientations (language-as-right, language-as-problem, and language-as-resource) form the theoretical foundation of this study. An ecological perspective is also utilized, focusing on how potential affordances for lesson planning found in contextual layers (e.g., the national curriculum or course materials) may affect their planning. The findings indicate that pre-service teachers generally employ a multilingual stance in their lesson unit planning, revealing a clear language-as-resource orientation across the cohorts studied. Furthermore, micro-level factors, such as course literature, have a more immediate impact than macro-level influences, such as the Swedish Language Act. New knowledge of how and why pre-service teachers understand multilingualism, as well as how they then plan lessons for English as a foreign language in the linguistically diverse classrooms of today, can be of value to all teacher educators.