A 6-foot-8, 240 pound combo forward, Oleka sat out last season while attending Cecil Community College in North East, Maryland.
A year earlier, Oleka averaged 25.6 points and 13.6 rebounds in five games at State College of Florida, Manatee-Sarasota in 2013-14.
Oleka, a Washington, D.C., native who signed with Texas in November of 2013 before being released from that National Letter of Intent, is expected to be able to play immediately for the Sun Devils, with two seasons of remaining eligibility.
Oleka is the second addition of the day for the Sun Devils and newly hired coach Bobby Hurley. Earlier, 6-foot-1 point guard Shannon Evans, committed to ASU while on an official visit to the school.
Evans played for Hurley at Buffalo the last two seasons, earning second-team league honors in the Mid-American Conference in 2014-15 with averages of 15.4 points, 3.2 rebounds and 4.6 assists while shooting 38.2 percent from 3-point range. He helped lead Buffalo to a leage championships and NCAA tournament appearance.
Evans will have to sit out this season and then have two seasons of remaining eligibility.
The Sun Devils are also strongly in contention for Maurice O'Field, a 6-foot-6, 215 pound small forward at Midland Junior College in Midland, Texas, a player who committed to Hurley at Buffalo in March but did not sign a National Letter of Intent.
O'Field told SunDevilSource.com he could visit ASU as soon as next week. He averaged 15.8 points and 5.0 rebounds last season.
The Sun Devils have eight returning scholarship players and one holdover signee, combo guard Andre Spight, a 6-foot-2 standout who averaged 15 points, 3.5 rebounds and 3.5 assists at South Plains Community College in Levelland, Texas.
With the additions of Evans and Oleka, ASU has 11 players slotted for its 2015-16 roster and two remaining spots to fill.
Earlier this week ASU released 6-foot-6 forward Sai Tummala and 6-foot-8 forward Connor MacDougall from their scholarships. Tummala is expected to graduate this summer and transfer with the ability to play elsewhere immediately for his remaining year of eligibility. MacDougall is likely to attend South Mountain Community College as a sophomore before transferring back to the Division I level. Neither player saw much action last season.
Hurley also released 2015 signee Dominic Green, a 6-foot-6 small forward from Hazen High School in Renton, Washington, from his Letter of Intent.