WorkflowLLM is a data-centric framework designed to enhance the orchestration capabilities of large language models (LLMs). At its core is WorkflowBench, a large-scale supervised fine-tuning dataset containing 106,763 samples from 1,503 APIs across 83 applications and 28 categories. WorkflowLLM fine-tunes the Llama-3.1-8B model to create the WorkflowLlama model optimized specifically for workflow orchestration tasks. Experimental results indicate that WorkflowLlama excels in orchestrating complex workflows and generalizes well to unseen APIs.