ɹᵻnˈeɪ nˈiːkoʊ hjˈuːbɚɾəs klˈɑːsən bˈɔːɹn mˈɑːɹtʃ fˈoːɹ, nˈaɪntiːnhˈʌndɹɪd sˈɪksti wˈʌn ɪn vˈɛlp ɪz ɐ fˈɔːɹmɚ fˈiːld hˈɑːki dᵻfˈɛndɚ fɹʌmðə nˈɛðɜːləndz, hˌuː pɑːɹtˈɪsᵻpˌeɪɾᵻd ɪn tˈuː sˈʌmɚɹ əlˈɪmpɪks: ɪn lˌɑːs ˈændʒəlɪs nˈaɪntiːnhˈʌndɹɪd ˈeɪɾi fˈoːɹ ænd ɪn sˈoʊl nˈaɪntiːnhˈʌndɹɪd ˈeɪɾi ˈeɪt.
René Nico Hubertus Klaassen (born March 4, 1961 in Velp) is a former field hockey defender from the Netherlands, who participated in two Summer Olympics: in Los Angeles (1984) and in Seoul (1988).