He has made recordings for the BIS, BMG Classics, Caprice, Danacord, dbProductions, and Phono Suecia labels.

Born in 1968 in Västerås, Ullén studied at the Royal College of Music, Stockholm, where his teachers included Gunnar Hallhagen and Irène Mannheimer.

Later studies at the Sibelius Academy in Helsinki included work with Liisa Pohjola.

His recordings include a collection of Chopin transcriptions and György Ligeti's complete works for piano.

Ullén has also produced the first complete recording of Kaikhosru Shapurji Sorabji's 8½-hour cycle of 100 Transcendental Studies.