William Blair Summer Analyst Internship

William Blair's summer analyst program is highly regarded for its hands-on approach and the genuine mentorship it provides. Interns are placed into specific industry groups and begin working on live transactions within the first few days, contributing to sell-side M&A mandates, pitch books, and financial analyses. The program includes a structured training component covering financial modeling, valuation, and professional development, alongside regular social events and networking opportunities. Class sizes are intimate, typically ranging from ten to twenty interns, which creates a collegial environment where every intern has meaningful interactions with senior bankers. William Blair assigns dedicated mentors and has a strong feedback culture, with mid-program and end-of-program reviews that provide actionable development guidance. Conversion rates are strong, often in the seventy-five to eighty percent range, reflecting the firm's genuine investment in selecting and developing interns who will become strong full-time analysts. The Chicago location provides a distinct advantage: interns enjoy a vibrant city with a lower cost of living than New York, and the Midwest culture permeates the program with a focus on collaboration and mutual support rather than competition. The firm's focus on growth companies means interns gain exposure to dynamic, founder-led businesses that are growing and evolving, providing more engaging work than the maintenance transactions that junior bankers sometimes encounter at larger firms.