Joseller "Yeng" Medina Guiao (born March 19, 1959) is a Filipino professional basketball head coach, politician, commentator and sports commissioner.

He was an alumnus of La Salle Green Hills and studied industrial engineering at the University of the Philippines Diliman, where he was a member of the Senior Men's Varsity Basketball team.

While Pumaren led the rechristened Sunkist Orange Juicers to two championships that year, Guiao had two forgettable seasons with Pepsi and then-renamed as Mobiline before leaving his coaching position in 1996.

In 2001, he would lead Red Bull to its first PBA title by defeating San Miguel 4–2 in the Commissioner's Cup finals with Antonio Lang as import.

Guiao would later repeat the same feat in 2002 Commissioner's Cup, leading Red Bull to a seven-game series victory over Talk 'N Text to defend its championship won a year ago.

In the 2006-07 Philippine Cup, Guiao led the Bulls to its ninth semifinals appearance in franchise history but lost to San Miguel in seven games.

The series saw physical confrontation between teams, even Guiao was ejected in Game 6 for elbowing Dondon Hontiveros and getting involved in a verbal exchange with SMB assistant coach Pido Jarencio.

The Barakos, with a depleted line-up, snatched a slot in semi-finals after it swept powerhouse team Magnolia Beverage Masters 2–0 in best of three quarterfinals of the 2007-2008 Philippine Cup.

As the coach of the Elasto Painters, he helped the team first by making them appear in the Semi-Finals for the first time in Franchise history in the 2010-2011 Governor's Cup.

Guiao once again led the Rain or Shine Elasto Painters to its 2nd straight (2nd overall) finals appearance once again, but lost to the Talk N Text Tropang Texters in a 4-game sweep.

After a six-year stint with two semi-finals appearances, Guiao left the NLEX Road Warriors to return to the Rain Or Shine Elasto Painters in September 2022.

Guiao became the sixth coach to head a PBA-backed national squad after Robert Jaworski, Sr. (1990), Norman Black (1994), Tim Cone (1998), Jong Uichico (2002), and Reyes, who had a 9th-place finish in 2007 FIBA-Asia Men's Basketball Championship in Tokushima, Japan.

He also helped the league gained marginal success from 1997 to 1999, with teams such as the Tanduay Rhum Masters winning titles and Blu Detergent signing-up Asi Taulava.

Trinidad and Guiao called Barangay Ginebra's upset of the Mobiline Phone Pals in 1999 All-Filipino Cup quarterfinals for Vintage Sports.

In August 2024, Supreme Court Justice Marvic Leonen granted the petition, directing the Pagcor to remit 5% of its gross income per year to PSC from 1993.