On March 15, 2023, Brendan Boyle was appointed the Chair of the Congressional European Union Caucus. In this role, he was responsible for enhancing diplomatic and economic relations between the United States and the European Union. Boyle underscored the importance of transatlantic ties and cooperation on global challenges such as climate change, security, and trade. His leadership in the caucus was aimed at fostering dialogue and partnership between European and American lawmakers.

On December 10, 2022, Brendan Boyle highlighted his support for legislation providing defense aid to Ukraine amidst the ongoing conflict with Russia. Boyle emphasized the necessity of supporting Ukraine's sovereignty and democratic aspirations in the face of aggression. He advocated for increased military assistance and economic sanctions against Russia, stressing the importance of international cooperation to uphold global security and counteract authoritarianism.

Brendan Boyle, along with Congressman Brian Fitzpatrick, co-launched the Irish American Caucus on January 20, 2022. This caucus was formed to foster collaboration and relations between the United States and Ireland, focusing on cultural, historical, and economic ties. Boyle, being of Irish descent himself, emphasized the significance of the Irish diaspora in America and the potential for strengthening bilateral relations through shared values and heritage.

On September 15, 2021, Brendan Boyle actively participated in the advocacy for comprehensive climate change legislation as part of the House Democratic Caucus. Boyle stressed the urgent need to address environmental challenges through substantial government action. He collaborated with fellow legislators to push for policies aimed at reducing carbon emissions and promoting sustainable energy solutions. His efforts were in line with the larger Democratic agenda to combat climate change and transition to a green economy.

Brendan Boyle publicly criticized the strategy employed by the Biden administration during the withdrawal of U.S. troops from Afghanistan on August 15, 2021. Boyle expressed concerns over the rapid collapse of the Afghan government and the ensuing humanitarian crisis. He called for comprehensive reviews and accountability regarding the withdrawal process to address its impact on both American interests and Afghan civilians. His position was part of broader bipartisan critiques voicing the chaotic nature of the withdrawal.

Brendan Boyle introduced the College Affordability Act on February 10, 2021, aiming to make higher education more accessible and affordable to American students. The bill proposed reforms in financial aid, investments in community colleges, and measures to lower student debt. Boyle's initiative targeted economic barriers to education, offering pathways for students from diverse backgrounds to achieve academic and career success without prohibitive financial burdens.

On March 3, 2020, Brendan Boyle introduced the End Corruption Act in Congress, a bill aimed at reducing corruption and increasing transparency in politics. The proposed legislation sought to impose new restrictions on lobbying activities, close loopholes, and create stricter rules around political finance. Boyle highlighted the importance of restoring faith in the political system and ensuring that elected officials work in the best interests of the public rather than special interests.

On December 18, 2019, Brendan Boyle voted in favor of the articles of impeachment against President Donald Trump. The articles charged the president with abuse of power and obstruction of Congress following an inquiry into the Ukraine scandal. Boyle's vote reflected his stance on the constitutional responsibility of holding the executive branch accountable and upholding the principles of democracy. The impeachment vote was a significant moment in American political history, highlighting deep partisan divides.

On November 6, 2018, Brendan Boyle was re-elected to the United States House of Representatives, this time representing Pennsylvania's 2nd congressional district following the state's congressional district map redrawing. Boyle emphasized his commitment to fighting for working families and improving public education, healthcare, and infrastructure. His re-election showcased his political resilience and the support he received from his constituents in a newly shaped district.

Brendan Boyle was sworn into office at the start of the 114th United States Congress on January 6, 2015, representing Pennsylvania's 13th congressional district. As a Democratic member of the House of Representatives, Boyle focused on issues such as education, labor, and international relations, serving on key committees and participating in legislative initiatives that addressed both local and national concerns.