Calvin John Oftana (born January 3, 1996) is a Filipino professional basketball player for the TNT Tropang Giga of the Philippine Basketball Association (PBA). He played college basketball for the San Beda Red Lions in the NCAA. He plays both the small forward and the power forward positions. He has also played as a shooting guard during college.
 Oftana was born in Danao, Cebu, but grew up in Siaton after his parents split up. He was raised by his mother along with his nine siblings. He did track and field, winning a 100-meter sprint in a district meet when he was Grade 6. He was also a volleyball spiker. When he got a growth spurt in high school, he was encouraged to try basketball. He played it in fiesta opens.
 When Oftana was in second year high school, he was discovered by Coach Mike Villahermosa of Asian College-Dumaguete. He convinced Oftana's mother to let Calvin play basketball for him. Under Coach Villahermosa, Oftana learned the basics of basketball. He also watched YouTube videos of shooting and dribbling drills to hone his skills further.
 Oftana first played for the San Beda Red Lions in Season 92. He won titles with San Beda from 2016–2018. He was a backup to Art Dela Cruz and Javee Mocon during this time, as he developed his work ethic.
 In Season 95, Oftana took on a bigger role. He had a near triple-double with ten points, ten rebounds, and seven assists in a win against the San Sebastian Stags. For that performance, he was given Player of the Week honors. He had a college career-best of 27 points and nine rebounds against the CSB Blazers. He won Player of the Week again after scoring a personal-best 29 points while adding nine rebounds, five assists, and two steals in San Beda's rematch over the Blazers. He won MVP after averaging 15.6 points, 8.2 rebounds, 2.7 assists, and 1.2 blocks, becoming the eighth MVP to hail from San Beda (the first since Sudan Daniel in 2010), and finishing 18–0 in the eliminations as they gained an outright Finals berth. They lost to the Letran Knights in three games.
 In 2021, Oftana declared for the PBA Season 46 draft. He was offered to be included in the special Gilas round during the draft, but he declined. He was drafted with the third pick during the first round by the NLEX Road Warriors. In their elimination round match against the Meralco Bolts, he had a career-high 34 points on 8-of-11 shooting on three-pointers and 12-of-18 from the field in 29 minutes of play; breaking the all-time record in three point attempts made by a rookie at eighth, erasing the 34-year mark of Allan Caidic at seven. He scored the game-winning layup with 6.1 seconds left as NLEX got an 81–80 win in the quarterfinals. On February 11, 2022, during a 100–110 loss against the Meralco Bolts, Oftana exited the game in the fourth quarter after suffering an injury. It was later revealed to be a fractured left ring finger, and was subsequently ruled out for six weeks. Despite not being able to finish the season, he still made it to the PBA All-Rookie team.
 In Oftana's first game since the injury (which was also NLEX's season-opener for the 2022–23 season), he scored 18 of his 20 points in the fourth quarter to help his team outscore the Terrafirma Dyip and complete their comeback win. Against the Phoenix Super LPG Fuel Masters, he made a three-pointer that sent the game into overtime. The Road Warriors won in overtime, and he finished with 22 points, 10 rebounds, seven assists, two steals, and two blocks. He then had 18 points against the NorthPort Batang Pier as NLEX claimed the 6th seed. In Game 3 of their Philippine Cup playoff series against the Magnolia Hotshots, he had 32 points, 9 rebounds, 3 assists, and 3 steals, but he wasn't able to score in overtime and Magnolia went on to eliminate them.
 On September 19, 2022, Oftana was traded to the TNT Tropang Giga in a three-team trade involving TNT, NLEX, and the Blackwater Bossing. Prior to playing a game with the team, he signed a three-year contract extension on October 4. In his first game with TNT during the Commissioner's Cup, he had 12 points and seven rebounds, but committed two costly turnovers in the fourth quarter and was whistled for fouling Paul Lee with 4.3 seconds left. Lee then went on to make two game-winning free throws for the Magnolia. Against his former coach Yeng Guiao, now with the Rain or Shine Elasto Painters, he contributed 15 points, eight rebounds, and four assists in the win. In a loss to Phoenix, he had his best game yet, with 27 points on seven three pointers in 38 minutes. TNT did not qualify for the playoffs that conference, their first since the 2018 Governors' Cup. 
 In Oftana's first game of the 2023 Governors' Cup, he had 17 points and seven rebounds in a win over Phoenix. After missing a game due to health protocols, he had a double-double of 14 points and 10 rebounds to help TNT take the win over Magnolia. Against the San Miguel Beermen, he had 14 points, six assists, and 10 rebounds, with the last rebound allowing him to make the game-winning putback basket. This allowed him to receive Player of the Week honors and placed TNT at the top of the standings for the conference. He also made it into the PBA All-Star Game as a replacement for Terrence Romeo. In the semifinals, he had 21 first half points in Game 4 against Meralco to send TNT back to the Finals. In his Finals debut, he had 16 points on 7-of-11 shooting, but still lost to Barangay Ginebra. He then had a double-double of 14 points and 13 rebounds as TNT tied the series in Game 2. In Game 5, he stepped up for injured RR Pogoy with 20 points on four triples as TNT took a 3–2 series lead. He was able to win his first PBA championship in the following game. For the 2022–23 season, he was named to the Second Mythical Team.
 In 2020, Oftana was called up to the Philippines national team to play against Thailand. In that contest, he scored 9 points on 3-of-5 shooting along with 4 rebounds and 4 assists.
 In 2022, Oftana made his return to the national team for the fourth window of qualifying for the 2023 World Cup. He played against Lebanon and Saudi Arabia. He also got to play in the fifth and sixth windows.
 Oftana then made his SEA Games debut in the 2023 edition. However, he suffered a Grade Two strain in his calf in Gilas' first game against Malaysia and was later ruled to be out for the rest of the tournament.
 Oftana was included in the 21-man pool for the 2023 FIBA World Cup. However, he was not included in the 12-man final roster. He did get to play in the 2022 Asian Games. In a win over Qatar, he scored 11 points, including three triples in the first quarter. The team then went on to win its first Asian Games gold medal in basketball in 61 years.
 As of the end of 2022–23 season
 In 2023, Oftana celebrated the birth of his first son Khalel Thaddeus.