Solís has a long academic and political career, culminating in his election as the first President of Costa Rica to be a member of the PAC.

Since May 2017, Luis Guillermo Solis has been under fire after a report accused him of corruptly expediting the legal process of Chinese cement imports in favor of businessman and owner of Sinocem, Juan Carlos Bolaños, in a case known as Cementazo.

[4] His maternal grandmother's family has Afro-Caribbean and Chinese roots, coming from Jamaica to Costa Rica in the early 1900s.

He attended Methodist High School in San José, where he was president of the student body, before studying history at the University of Costa Rica, where he earned a degree with academic honors in 1979.

During this time, Solís worked with the Arias administration and eventually became director of the Center for Peace and Reconciliation (CPR for its Spanish initials).

[10] Among his aims, Solís claimed he would clean up corruption, create major investments in infrastructure, and shore up Costa Rica's universal health care and social security system.

[25] Delegations from more than 80 countries attended his inauguration at La Sabana Metropolitan Park, including Prince Felipe de Borbón of Spain, Evo Morales of Bolivia, Rafael Correa of Ecuador, and the Secretary General of the Organization of American States, José Miguel Insulza.

[26] Solís said, in Costa Rican vernacular, that he is taking over a "weed farm" (finca encharralada),[24] pointing out growing income inequality and poverty, as well as a national teachers' strike.

Of greater concern is the fact that a full 46% of the budget will require financing, a step that will increase the debt owed to foreign entities.

Moody's was also concerned about the "lack of political consensus to implement measures to reduce the fiscal deficit [which] will result in further pressure on the government's debt ratios".

[30] In late July 2017, the Costa Rica Central Bank estimated the budget deficit at 6.1 percent of the country's GDP.

[31] A 2017 study by the Organisation for Economic Co-operation and Development warned that reducing the foreign debt must be a very high priority for the government.

Such steps are essential, Solís told the nation, because it was facing difficulties in paying its obligations and guaranteeing the provision of services.

"[31] "Despite all the public calls and efforts we have made since the start of my administration to contain spending and increase revenues, there is still a gap that we must close with fresh resources," he said.

The crisis was occurring in spite of growth, low inflation and continued moderate interest rates, Solís concluded.

[28] The past generated two different economies: one very dynamic, modern and generally oriented toward international markets, with limited possibilities for new sources of employment, and the other, traditional, which created many jobs with low pay where small and medium-sized businesses concentrated.

[34] Past governments have avoided collecting taxes on large companies and high-income earners, leading to budget deficits which Solís claims his administration will fix through better enforcement.

In May 2014, he ordered that a rainbow flag be flown over the Presidential House as a show of solidarity with gays on International Day Against Homophobia and Transphobia.

[35] Solis has five children from his previous marriage to his first wife, Nancy Olive Worsfold Richards (1987–2006): Monica, Cristina, Beatriz, Diego, and Ignacio.

[38][1] Solís is not married to Mercedes Peñas Domingo, but during his administration, she was altogether considered the First Lady of Costa Rica.

[35] As of July 2020, Solis has been named the Interim Director of the Kimberly Green Latin American and Caribbean Center at Florida International University.