After appearing in numerous commercials, he debuted on TV with a small role in the 1985 NBC TV movie "Between the Darkness and the Dawn". The actor did some feature work, and went on to star in 1988's ABC Disney Sunday Movie "14 Going on 30", playing the grown up incarnation of a young boy who speed ages as the result of a science experiment gone awry. That same year he took on the much heavier role of Navy diver Robert Stethem, the lone casualty of a TWA hostage flight, in the fact-based "The Taking of Flight 847: The Uli Derickson Story" (NBC). The actor brought a sweet affability and an all-American ingenuous air to his roles, often playing pleasant and well-meaning but unexciting characters. He had recurring roles on the short-lived CBS series "WIOU" in 1991, and was featured the following year as the boyfriend of elder daughter Paige on the ABC family drama "Life Goes On". He finally got a regular role as Thumper, the womanizing sportscaster, on the ill-fated cult favorite "Grapevine" (CBS, 1992, a look at modern relationships through the eyes of three gossiping friends. From 1993 to 1994, Eckholdt was the likable love interest of wronged resident good girl Jane on "Melrose Place" (Fox) and during that time was also featured in a recurring role of manipulative associate Patrick Flanagan on the final season of NBC's "L.A. Law". The TV veteran next took a regular role as self-made millionaire Robbie on the ABC comedy "it's like, you know ..." (1999), starring with Jennifer Grey and Chris Eigeman in this satire on life in Los Angeles. Robbie, often shallow and opportunistic, still remained a surprisingly sympathetic character, due mainly to Eckholdt's charming presence and nice guy delivery.
Eckholdt first appeared on the big screen in 1986 with bit parts in "About Last Night" and "The Wraith". Two years later he was featured in the Molly Ringwald vehicle "For Keeps" and he next starred in the little-seen 1989 teen adventure feature "The Runnin' Kind". Busy with television work, Eckholdt didn't return to film until 1999, when he had a featured role as Robin Wright Penn's ex-husband in the romantic drama "Message in a Bottle".