“I set a clear vision, execute with precision, and shape performance management that delivers outcomes that matter.”
Leslie Koutroulis is a seasoned finance executive and board leader whose career reflects a rare combination of operational depth, strategic foresight, and unwavering commitment to principled leadership. With more than three decades of experience—25 of those at T-Mobile—she has built a reputation as a trusted advisor to executives, a disciplined steward of capital, and a transformative force behind large-scale enterprise growth. Known for bringing clarity of vision and an operational focus that consistently delivers outsized results, she is respected across boardrooms and organizations for her steady judgment, integrity, and impact.
Currently serving as Segment CFO for T-Mobile’s fastest-growing business unit, Leslie operates at the intersection of finance, strategy, and innovation. In this role, she partners closely with presidents, C-suite leaders, and board members to guide decisions for a multi-billion-dollar segment. Her leadership spans long-range planning, capital allocation, and performance management, all aimed at sustaining double-digit revenue growth while maintaining operational discipline. Her ability to translate complex financial data into actionable insights has made her an indispensable contributor to enterprise-wide strategy.
Leslie’s career trajectory is marked by continuous advancement through increasingly complex and high-impact roles. Beginning her journey in operational and financial planning positions, she steadily rose through the ranks, taking on leadership roles across retail finance, engineering, IT, and technology divisions. Each role added new layers to her expertise, from developing the first profit-and-loss reporting systems for retail operations to managing enterprise-wide financial transformations that improved forecasting accuracy and efficiency.
A defining chapter of her career was her pivotal role in the T-Mobile and Sprint integration, one of the largest and most complex mergers in the telecommunications industry. Leslie played a key role in driving financial oversight and execution, contributing to the realization of $5 billion in network synergy run-rate benefits and accelerating an additional $1.5 billion in value. Her work not only ensured financial rigor during the integration but also helped position the company for long-term competitive advantage.
Beyond her executive responsibilities, Leslie has extensive experience engaging with boards of directors. For over a decade, she has prepared and presented financial strategies, long-range plans, and performance updates to T-Mobile’s independent directors. This exposure has deepened her understanding of governance, risk management, and fiduciary responsibility, positioning her as a highly effective and board-ready executive.
Her board experience extends beyond the corporate environment into nonprofit and academic sectors, where she has made a meaningful impact. Leslie has served as Board Chair of Bellevue LifeSpring, a nonprofit dedicated to supporting children and families in need, where she guided financial stewardship and organizational strategy. She also contributes to the Seattle University Finance Advisory Board, helping shape future leaders, and has served on T-Mobile’s Women in Technology Board, championing diversity and STEM initiatives.
Leslie’s expertise spans a wide range of critical financial and strategic disciplines, including capital planning, enterprise risk management, financial controls, and transformation initiatives. She has led organizations through system implementations, operational restructurings, and performance optimization efforts that drive measurable results. Her ability to align financial strategy with business objectives has consistently enabled organizations to scale effectively while maintaining strong governance practices.
Her industry focus is rooted in telecommunications, technology, and utilities—sectors that demand both innovation and disciplined execution. Leslie’s deep understanding of these industries allows her to navigate complex regulatory environments, evolving market dynamics, and technological disruption. She brings a pragmatic yet forward-looking perspective that is invaluable to organizations seeking sustainable growth.
Internationally, Leslie has experience with global reporting structures and maintains a personal connection to Greece, where she spends time with family and embraces her heritage. She is conversational in Greek, reflecting her appreciation for cultural diversity and global perspectives. These experiences enrich her worldview and enhance her ability to operate in increasingly interconnected business environments.
At her core, Leslie is driven by a desire to make a meaningful impact. Her involvement in nonprofit work and her passion for supporting families and children in need demonstrate a commitment to service that extends beyond the corporate sphere. As she seeks additional board opportunities, she brings not only technical expertise but also a genuine dedication to helping organizations thrive and fulfill their missions.
Leslie Koutroulis stands out as a leader who combines financial acumen, strategic insight, and authentic humanity. Her career reflects a consistent pattern of delivering results, building strong teams, and guiding organizations through complexity with clarity and confidence. Whether in the boardroom or the community, she exemplifies the kind of leadership that drives lasting value.
Character:
Leslie demonstrates integrity and humility in every aspect of her leadership, consistently aligning her actions with her values. She fosters trust through transparency, accountability, and a genuine respect for others. Her commitment to service and community impact underscores a deep sense of purpose beyond professional success.
Knowledge:
With over 30 years of experience, Leslie possesses a comprehensive understanding of financial strategy, governance, and operational excellence. She continuously applies her expertise to complex challenges, delivering insights that drive meaningful outcomes. Her depth of knowledge across telecom and technology sectors positions her as a highly informed and credible leader.
Strategic:
Leslie excels at connecting long-term vision with actionable plans, ensuring sustainable growth and value creation. She approaches decision-making with a balance of analytical rigor and forward-thinking perspective. Her ability to lead through transformation and complexity makes her a powerful strategic partner.
Communication:
Communicating with clarity, precision, and purpose, effectively engaging stakeholders at all levels. She has extensive experience presenting to boards and executive teams, translating complex financial concepts into clear narratives. Her approachable style fosters collaboration and alignment across diverse audiences.
